1) check the award chart -- http://mileageplusupdates.com/images/United-Award-Chart.pdf
2) united metal is significantly cheaper than partner airlines. to save, be sure you're looking at united flights.
3) of course, only look for "saver" awards -- "standard" awards are shit.
4) you shouldn't be spending points on a cheapo $320 flight tbh
Yeah, only use it for bigger flights. International preferred. I flew 10 hours to AMS for 25k points in economy. I can fly 1 hour to Oregon for the same points. No-brainer.