While what newbie says about hotel transfers is true (9 potential hits is pretty amazing) keep in mind most of the transfers are hugely destructive in terms of total value of the points/miles. E.g. even for the most rewarding hits (5000 miles a piece) you are losing total points for the hotel transfers. If you have any use at all for the hotel points this is not such a great route. I mean 10,000 Hhonors points going to 850 US miles is pretty crappy, even if you're getting 5000 US miles in the process.

The exception of course is if you have orphaned points. Also you're right that e-rewards might be okay for this, but it pains me to think of the time it would take to get to $150 on e-rewards for 10,000 Hhonors points just to get 5,850 US miles out of the deal.

If the transfer ratios were better hotel transfers would be a great option, but as it stands they're pretty bad in my opinion.

I think one of the great tricks is getting cheap rentals. I got 4 rentals this time, all for under $20 each. Those are pretty cheap hits, if a little time consuming, but if you can work them into your schedule regularly then they're pretty easy.