My way For freerolls...

Well my experience shows so far that you have to use 2 tactics...

First and risky... You call every blind raise with evry hand you go and oyu hope to get a good pair or threesome down,then after a check the possibilities of a big raise from the raiser is 90%propably...and you call and you make quicly a big stack

Scend and secure..Yu just wait for a big pair or two good cards suited and only cal then..

But for freerolls ,cause it's free just use the first methom..i think it worth it ;)