Following on, as others have alluded to LM is best used for very straightforward, point-to-point redemptions. There are specific sweetspots that people use LM for - Asia - Australia for 40k in J on BR/NH for example, but you should only be purchasing LM if you can directly see award availability on their website, at the very least (conferring with AC/UA is better!).
Had a bit of success recently - after cancelling a BR TPE-BNE booking and getting slugged with the 200USD cancellation (actually relatively painless to cancel - I just called the US call centre with my skype number, and was connected quite quickly), I managed to book TK for LAX-IST-VIE early next year for 63K LM + ~60USD. I was trying to get to Zurich, but even though there were flights from IST-ZRH that lined up it wouldn't work, and on the day there was no LX or LH availability 
