Magnus Muhlenbock collected some easy club tricks:
Throwing one a bit higher with a double flip is probably a good place to start. Try it with just one club before you try it in the pattern. Then there's "floaters," throws with no flip at all. Just sort of scoop the club up.
Under-the-leg isn't too hard. Again, try it with one club first, then try to start you pattern with that throw, then try ending a pattern that way. Finally, try it in the pattern. Lift your leg high, bent at the knee, and make all your throws a little high to give yourself a little extra time.
Have fun!
I think that you were requesting some easy three-club tricks to learn. Easy three club tricks? There are lots! OK, maybe I didn't find them so easy to learn, but then again, it took me quite a while to get a three-club cascade down!
Try doubles. Every once in a while, throw one higher and have it flip twice instead of once. Do it with both hands. You can do every throw as a double if you want to. It looks pretty.
Then there is the "wing-one-up-as-high-as-you-can-and-catch-it-and-the-non-jugglers-think-you-are-o-so-cool" one.
My favorite is sort of like a three ball half-shower. Practice throwing one over your head from the right to the left hand. It should flip twice and the audience should be able to see the flip (ie. it is flipping in a different direction than normally, plus it is over your head. I would wear headgear when learning this one.) If that makes no sense, ask anyone about doubleoverheads and I am sure that they would be able to explain it much better than I can!
If all of these tricks you can perform flawlessly already, then maybe you should look into asking for some "hard three-club tricks"! I can't do any of those yet! Happy juggling!