Well done on coming this far, but you've probably been playing for hours for an amount which equates to less than minimum wage. The key focus now is hitting the final table - this is where the decent payouts come.
At this stage the blinds are often crippling - relying on cards alone will see you out of the freeroll. You're going to have to bluff a lot, but don't try and get in the way of the chip leaders too much 0 you'll get called more often. Equally watch out for the small stacks - they've got nothing to lose either in calling, looking for a double up. Don't take it on yourself to eliminate the small stacks, let the big stacks do that. They have enough chips by this point to call an all-in while still not hurting their stack too much.
The bread and butter of this stage of the tournament is blind stealing. If you're on the button or near and you're the first to call the big blind, make sure you raise most of the time in order to steal the blinds. Capitalize on the weakness of others.
Mostly in the final stages you're just using the same techniques you used for the mid stages, but finer tuned and with more finesse. These techniques will often take you to the final table, but remember you won't always make it there.
Conclusion
Practice makes perfect. You will learn a lot through just trying to learn how to use these skills to perfection, and most importantly you'll adopt your own ways of doing things. Adapt these techniques into your winning techniques!