How do I stop onigiri from falling apart? I'm experimenting with Japanese cooking, and I can't seem to get the hang of making rice shapes.

I want to make an onigiri rice triangle with a filling. The theory is simple enough: make rice and let cool, take rice in hand, dig a small crater, place filling in crater, fold around the filling and shape in to a triangle.
In practice, I must be missing something, because it simply falls apart. I'm not sure if this is the technique of folding, shaping, or even cooking the rice.
Things to try


Rice should still be warm
Handle rice gently, don't squeeze it


Does it fall apart because it is sticking to your hands? If so:


Use warm salt water on your hands (not dripping wet hands though)
Rinse the rice more before cooking to remove excess surface starches. The process is: Rinse in bowl of water, gently tumble, let stand 20 minutes, change water. Repeat until rinse water runs clear


If this still fails to solve this sticky issue, you can use cling film (plastic wrap) as a guide and release agent on your hands. Peel the plastic off as you wrap the nori on