After about 3 inside loops in a row your lines are gonna start feeling a little stiff. After a few flights of doing inside loops, try inverted -- half a loop then level out. You might want to try some wing overs first though to get used to the idea of flying up higher if you haveln't done that already.

A good trick for doing inverted without disaster is to hold the handle horizontally with your thumb towards the direction of flight rather than vertical. I'm a lefty, so this is real easy for me. If you freeze up and just go brain dead, the rotation of the model will naturally start to pull on the down line and move the model higher away from the ground. Once you're up around 45 degrees you can just hammer half an inside loop and bail out back to level flight.