Best general advice I'd give to anyone hoping to book nice flights on UA with miles: Calibrate your expectations.

There's a huge industry (actually, several of them, including the airlines themselves, banks/credit card companies, and bloggers) who all make a lot of profit by making you think you'll be regularly zooming off to Paris and Bora Bora in first class, staying at 5 star resorts, have attractive partners, and generally live what's been sold as "the good life" just by signing up for a credit card or two and using your card for a little shopping.

The dirty little secret is that getting the miles is the easy part. The airlines have all worked very, very hard to make it nearly (or completely) impossible to get what you want. They are working harder and harder at this and being more successful with each passing month.

Keeping your expectations low is the best way to succeed.