Hi, I mostly fly between San Francisco and Madison, Wi to go to and from school and I was wondering what the best way to add a segment onto my journeys so I can get more miles without raising the price too much. Thanks so much for the help.

The best way to add miles to your journey would to go east MSN-ORD-IAD-SFO. You could try something like MSN-DEN-IAD-SFO, but that looks like it will become too expensive. Since you're a student like myself I would imagine you could be slightly flexible on some of your travel dates and know them in advance. Start looking early on using ITA http://itasoftware.com/ and then track routings using a softwate like YAPTA. With ITA you can do a search where you force extra segments. To do this for, enter "MSN :: UA UA UA UA" in the "from" and this will add two segments; reduce by one "UA" to only add one segment. You can do this both ways. Good Luck.

Welcome to Flyertalk jdl196. First thing is to decide do you want extra miles or extra segments -- sometimes you don't get both (eg. ORD-DEN -SFO is two segments -- assuming both flight numbers are different -- but the same miles as ORD-SFO nonstop.) 1wfudeac's suggestions are great but I believe UA routing rules will not allow his trip routing -- therefore from MSN I'd say "go West young man". MSN-ORD-SEA-PDX-SFO ( as an exanple) will give you segments and miles.
The trick is, of course, finding all the segments with available fare buckets to keep the cost under control. I've also found that on occasion using the UA web site (.bomb as its often called by FT's) and putting in city-pairs with "2-stop" default will sometimes give you surprisingly creative routings and decent fares. Yes, its a lot of work -- but thats part of the game we all play.
Good luck.