I use psi balls for a lot of things
Healing is a good thing to use them for. Simply guide the ball into the injured area and see it ether absorbing the injury or melting into it and healing it.
You can also plant thoughts/emotions or a certin type of energy into them and guide them into yourself or others. I used to throw energy balls of happiness at random people in public places to send good things to them.
They can also be used for banishing evil, throw them at a negative spirit and away they go
They can be used to empower items too