I find that a lot of Frost players (even some really good ones) tend to make two primary mistakes:
1) They under-utilize her air-dash, which, IMO, is the secret cornerstone of her mobility.
2) They fall into the trap of trying to squeeze EVERY facet of her game into setting up a 50-50. As a result, a lot of Frost players implement their gameplay in remarkably similar ways, and this unfortunate copycat syndrome tends to make her unnecessarily predictable and easier to defend than she probably should be. Also, their devout loyalty to creating 50-50 situations takes the game down to chance, even in situations where they are at an advantage and would probably benefit from simply employing a more fundamental approach. I feel that certain aspects of her game (block-strings, throw setups, etc) are highly under-appreciated and undervalued . I think as the game progresses, we will see more varied Frost play at higher levels of competition, which will elevate the character to currently unforeseeable heights.
But anyway, enough of me going on and on about Frost on the Bane forum.
Bane rules.