Higher the field & lower the prize, the more uninteresting it becomes for me personally. Previously I'd play any freeroll I'd set my eyes upon but now I'm selective.
Strategy wise I'd play tight in the early stages. You'll see many retards shoving with absolutely nothing but getting lucky. What you have to do is, choose your spots and take the chances.
Lets say for an instance you have pocket 9s at the button and 3 people shove before you preflop. Unless you cover them by a margin, I'd personally fold my 9s.
Only play monsters at the beginning and play them very aggressively. You can take advantage of positional play as well. Once you've doubled,tripled your stack try to see the flops cheaply with suited connectors as well. If you hit the board then you can get chips off easily from smaller stacks.
Luck is needed obviously but with some patience you can get there eventually. It's almost as same as a regular tournament + a couple of insane players.