Seems that its not easy to reach from Kunming. There is no direct flight and i can only book two seperate flights at ctrip.com, not one connection flight.
Train will take 36 hours. What would you do? Fly to Hangzhou and take a 3 hours bus to the mountain? Or book two flights and still need to get to the mountain from the airport?

Yongshuo is my favourite place in Chine. It is in the South and is not cold in December. The scenery is amazing and if you are into mountain cycling or rock climbing it is the best place to go. You can also spend a day in Guiling, before getting to Yangshou (it's a bus ride).

Ah, but he told us that he visited Guilin (one would presume Yangshuo, as well) during a previous trip, and aspires to check out different places.

Yes, I was in Yangshou december last year. Maybe I will go there in the future again, but China should be big enough to see something different this time.

I agree that Yunnan is a great place to visit in December, as is Huangshan. Note, however, that, though neither is Harbin in winter (-22F), they're not exactly warm. If you go up into the mountain areas surrounding Lijiang, you'll need a warm coat (you can actually rent one in Lijiang!). It's rather chilly in the morning though, happily, there are plenty of nice little tea shops you can duck into to warm up. Huangshan is, of course, a mountain ("Yellow Mountain"). I've been there in December. Though, during the day, it's quite comfortable in full sunlight, after dark and at sunrise it's cold.

That said, these are great places to visit (along with Kunmin and Dali) and offer the added bonus of being off-season and not, therefore, too crowded.

Maybe I should concentrate in one destination. I dont like to be in hurry, so to visit Yunnan should fill two weeks.
I read that I should stay at least two nights in Lijiang, would you stay two nights in Dali, too or is one enough?
How realistic is it to buy a train or bus ticket from Lijiang to Dali and from Dali to Lijiang at the same day I want to ride in off season time?
Is it recommended to walk along the tiger leaping gorge in this time of the year?

I think spending two weeks in Yunnan is a very good idea. I'd be inclined to allow more than two nights in Lijiang (we were there for seven, as I recall). Lijiang is a funny place. I don't know if you know its recent history. Lijiang was a medieval Chinese town that had been virtually untouched for 400 or more years. About 10 years ago Zheng Ymou, the famous Chinese film director, shot a period film there and Lijiang became famous within China. It has since become a major tourist attraction but, almost exclusively, for the Chinese. Accordingly, we found Lijiang interesting on several levels. It's a beautiful ancient town (notwithstanding the fact that virtually every building is given over to tourism), and it also let us see how the Chinese do tourist attractions (basically, the same as the west, but with Chinese-appealing souvenirs, snacks, etc.). Lijiang has an old theater in which a Chinese orchestra (traditional instruments) perform. We loved it and I'd rate it a "must do." There is also a regional "pageant" staged by Zheng Ymou himself that was worth the day trip. Very nearby Lijiang (quick and easy taxi ride) are a couple of other heritage towns that, though smaller, are equally beautiful and considerably less touristy.

We spent one night in Dali, but could have easily spent more. Dali is more of a city but, like Lijiang, a destination that many Chinese tourists like to visit. Two nights is probably sufficient.

I'd also recommend spending time in Kunmin, which you will almost certainly have to travel to anyway if you're going to fly from one of the major cities to Dali.

As for getting from Dali to Lijiang, it is a very mountainous area. I can't speak for the train, but I suspect a bus would be a terrifying experience on the narrow and twisty roads. We hired a car to drive us, which turned out very well. The area is home to the Bai people, an ethnic minority with a very distinctive style of dress, including some really elaborate and beautiful tie-dye. There are some shops along the way that sell these and other local crafts at very low prices, and we were able to make some stunning purchases. If you elect a car or taxi, I'd recommend learning the Mandarin for, "Please, not so fast!" :)

It is too far a distance, and there is too much to see at both locales to try to do Dali as a day trip from Lijiang, or vice versa.

Yunnan is also famous for a distinctive tea called pu'er, which is made from fermented tea leaves. My wife (who is Chinese) likes it, though I have to say it is probably an acquired taste. There are, however, a number of shops that sell pu'er and, for a reasonable charge, can provide a tea-tasting that will allow you to try (and learn about) the various kinds of tea available in the region. Note that this is NOT the infamous "tea shop scam" that is aimed at tourists in Beijing. These are fixed-price tea samplings (with aim towards selling you tea if you like it, though it is not hard-sell -- it's simply available if you want it) and was quite fun for both myself and Mrs. PTravel.

Thank you. Would you book a flight from Shenzhen to Kunming for 630RMB including Tax or a Flight Shenzhen Chengdu, Stopover for one night and then fly direct Chengdu Lijiang for 1120RMB? Almost double the price but I will get one night in Chengdu and i dont have to visit Kunming two times, only one time to fly to Beijing on the way back. Train Kunming Lijiang cost 218RMB Softsleeper? Could subtract it from the higher costs, so there are only272RMB real difference.
Only the times are not the best, departing 9am in Shenzhen and 7:15 in Chengdu. When should I start from Hongkong Island to Shenzhen airport to arrive there at ~ 8am?

I've not been to Chengdu, though it's on our list of, "one of these day we'll go" (we go to China at least once a year). Our philosophy (which is not everyone's) is to schedule so we never have only one night in a place. Our minimum is two so that we have at least one full day to explore.

Believe it or not, despite visiting China regularly since 1994, I've never taken a train (except for the express from Shenzhen to Guangzhou and back -- my in-laws live in Guangzhou). My wife absolutely refuses to travel by train and, evidently, the Guangzhou express, which is only an hour ride or so, is not typical of Chinese train travel. She says that both the stations and the trains are far too chaotic.

As for getting to Shenzhen airport from Hong Kong, it depends on the day of the week. We have a private driver that we use whenever we fly into Hong Kong, as our first stop is always a few days in Shenzhen to visit friends. Because Shenzhen has become a bedroom community for Hong Kong, the vehicle border crossing can take some time. Also, procedures vary -- sometimes I can stay in the vehicle (always a minivan) and we drive through a tollbooth affair equipped with cameras and sometimes I have to get out and wait in line in a building. As I am most often meeting my wife in Shenzhen and don't speak Mandarin, I have no idea as to why the process isn't consistent.

The Shenzhen airport, like most modern airports, is a quite a bit outside the city of Shenzhen which, itself, is quite large. My recollection is that it took us about an hour from the center of Shenzhen.

For an 8 am departure, you'll be going against traffic, so you won't have to factor that in as you would if your were trying to make a 7 pm flight.

Are you transferring directly? If not, I'd recommend over-nighting in Shenzhen (unless you've never been to Hong Kong). Hotels are less expensive, and Shenzhen has some absolutely extraordinary restaurants.

Will stay 3 nights in Hongkong and then take a flight from Shenzhen. This is my first stay in Hongkong, so I will stay directly in the city. I'am not planing to stay a night in Shenzhen. If I take the evening flight from shenzhen to kunming I could stay one full day in shenzhen, should be enough.

You're really missing out; the "local" train experience is fascinating on many levels. As much as I dislike the negatives, I can't recall regretting a single train journey (including my 1995 weekend trips between Nanjing and Shanghai sitting on newspapers).

ETA: If you search my FT post history with a razor comb, you'll realize that I've dissuaded a handful of people from doing 20+ hour hard rides on hard seats. My position wrt this unchanged, but there are many happy middle grounds (e.g. my 8 hour hard seat trip between Dunhuang and Jiayuguan was pretty close to my breaking point, but I liked it).

I was in and around Lijiang for 5 days which i thought was sufficient. Day 1 was spent walking through the old town and touring the black pool and elephant hill. Day 2 we did heritage villages north of Lijiang. Day 3 we went to Tiger Leaping Gorge (not worth it in my opinion, i thought Milford Sound, NZ was far more impressive). Day 4 we took the morning train to Dali, toured the Pagodas, ate lunch by the lake, and in the afternoon walked through the old town before catching the late afternoon train back to Lijiang. Journey takes about 1.5 hours. Not much difference between the two towns IMO, Dali is more authentic and definitely has more of a backpacker vibe, but Lijiang was more beautiful. Day 5 we toured Lijiang a little more, swam in the heated pool (highly recommend the Crowne Plaza) before heading out.
BTW, Lijiang has by far the best Chinglish signs of any place i've been to in China.

Try to book the cheap flight from shenzhen to kunming, but ctrip send me an email that this flight is sold out now. So the Transfer Flight via Chengdu to Lijiang is now the best option, almost the same price than I fly to kunming first and take the train up.

Edit: Will book the Chengdu Flight now. A friend will show me the city that day, maybe I can see the much interesting things with a local guide in that short time :)

Flights confirmed :)
So, now I have to reach a 9am flight from Shenzhen. My Hotel is Ibis North Point, Hongkong Island. First train to Lo Wu start 06:13, journey should take 66 Minutes to the border, so I could be there at 07:19. If it take up to 40 minutes for the border control there will be no chance to reach the flight. So I have to cancel the last hotel night in Hongkong and move to Shenzhen.
Is it a good idea to spend the night in the near of the airport or should I stay somewhere else in the city?

I'm a big fan of the Crowne Plaza in Shekou (I think); it's halfway between Lohu and the airport, and the surrounding area has lots of trees. Whenever I stay there, I end up eating the hotel's restaurants because there isn't much else in the area, but they are good enough (oh, and the breakfast is quite nice). There is direct subway access to the airport now; I still prefer taxis.