Practicing turns with your rudder IS a good idea. You never know when it could come in handy. But it is not the way a rudder should be used. By all means, continue to practice it, but don't expect your airplane to turn without doing some other weird things as well.

Now, if you want to learn to USE your rudder in a more appropriate fashion, I would suggest three maneuvers: 1 a stall turn. 2 a Knife Edge. 3 a Slow Roll. And 4 Side slipping a landing.

Side slipping is probably the toughest of the four, but it's the one that will be the most beneficial to your skills. Mastering this technique really comes in handy when you have to do cross-wind landings.