I subscribe to First Class Flyer newsletter and apply many methods that they suggest in getting award tickets. If I'm not getting at least .03/mi, it's a bad deal as you can buy the miles for that or less. I also look at the cost of fees to get the "free" ticket vs. buying the ticket. Except for Southwest for domestic flights, I only get International Business or 1st Class as that is where you can get anywhere from .05 to .15/ mi.

I just completed an around the world flight BOS-DUB-IST-KUL Business Class and return SIN-HKG-ORD-BOS 1st Class for 160,000 miles and $380 booked through UA. $200 of that was a change fee to get the 1st Class tickets when they became available. I valued this at .12/mi.