>>Please, only reply if you're over the age of 13 (mentally, not physically!)
What about if you are 20, but took down the part of your website that said you were 20 because everyone guessed you were 13 due to your posts?
Ok, seriously...
As for handling cresties, oh, I wish I could help, my little girl has "gecko ADD", always has. We had a hard time handling her early on, sometimes we even had to box her to clean her cage. Now, admittedly, it was mostly our fault, we didn't spend enough time with her, we expected leopard gecko tameness. Now what I can offer you is after about a year she began to settle down quite a bit and it is a lot easier.
A friend taught me a trick to slightly angle your arm straight out with a slight incline and they are naturally inclined to crawl up it, add the next hand at your biceps and you can do something similar to the "there is always another hand" game for leos. I've never really gotten the hang of it, but my arms are pretty short. I never handled my girl early on without a "back up", someone I can call if she jumps too high. I also started holding her close to the ground, because honestly she was often too surprised when she "got away" that she was corralled within a foot of where she jumped. I can also tell you that is it fairly easy to tell when they are preparing for a superman leap, you'll feel them brace and tense, if you change your body position you can interrupt most flying leaps that way.
Another good idea is, if possible handle them somewhere you feel comfortable. (Heck, head to the shower, it works for crickets.) When she was really small, I would handle her over her transport box, that way if she jumped, it was usually either into or onto the box. I would then watch her, but leave her alone until we were done with the cleaning... slowly she would spend more time with me before leaving and she also saved the pooing for the box, which I appreciated. 
Mostly now we just spend time hopping between hands, about a foot apart, slightly different elevation and she just hops and flops.
Another trick that works with leos too is to cage their heads if they get too high. Cup your hand like a cave to stop the upward mountain climbing.
I know I am not much help, but here is some of the things that I have learned. I hope someone has some magic training technique, because I would love to spend even more time with my little girl. But let me tell you, it is so worth it... holding a crested in one hand and feeding her fruit from a teaspoon with the other... so worth it. Good luck.
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0.1 Albino Leo Gecko
0.1 Crested Gecko
1.0 Dear Boyfriend
Departed: Harvey and Spock
