There are lots of options. The first is to loosen up your play on the bubble, which is the opposite of what 90% of players do, to make some key steals.
Also, you cant just become a rock once your in the money. Thats a sure way to finish middle-money, but you wont be squeezing the most value out of your cards if you only play the nuts.
If you are making the bubble pretty consistantly then i'd just suggest sticking to the game that got you there. Perhaps just get a little more aggressive.
Check out some threads on 'changing gears', and vary your game depending on tourney position and what stage your at.
If your short-stacked after the bubble, dont be afraid to get your chips in with reasonable looking
hands. Its back to basics there, as if you've just started the game and accumulating chips for survival!
The difference between cashing in last spot and cashing in mid-spot is often just a few dollars, whereas once you've made the top 25% of the cash spots your winnings can take steep step upwards. This fact means you can afford to gamble a bit.
Decide in each tourney (depending on the return on your investment) whether your going to play to cash, or play to win. Both are very different games.