freerolls can be tricky, you need to understand practically everyone in the early levels of the freeroll is a fish - they will call almost any raise / bet and are not too easily bluffed so i wouldnt try that often. Play a good solid game, don't overcommit bigger pairs (QQ or less) with an average stack - if you're short - put it in, if your way up - apply the pressure...but understand these people with A3 or A7 offsuit will call you're move. I tend to go to raised flops with these big
hands and the fish will hang themselves. I played 5 $10 on demand freerolls on ACR last night and tho i did not cash in any of them, i finished inside the top 50 in 3 of them. Its a good way to practice some of your mtt game. Anyhow, my strategy for winning:
Play very tight and aggressive early - bet very good hands preflop and charge the fish to play their junk.
When you make your hand - cbet reasonable sizings, most fish will call 1/2 pot - once you have them hooked take them to value town and send your stack soaring. I tend to double up within the first 15 mins or so if i get the right hand and the right player.
Once you build a stack of 2.5x + what you started with - apply pressure - play more speculative hands like j10s, q10s, qj, a8s, etc. Limp and look to call a raise with smaller pairs - overall become more active but remain fairly tight in your play - you are still trying to build a monster stack.
Lastly as i said, most of these players are fish...rule #1 - do NOT
bluff the fish, while they can be bluffed this is a free tournament - they will not be folding very much i promise you.
Good luck! Have fun