I don't know if there is really a "rule book" for this.. you'll work out what works best for you after doing it a few times.

For me.. i just keep my head in the normal position and stand directly under the running water, so the pressure of the water is just pushing the piece right down to the head, rather than putting my head back and having the water run from the front to the back, putting unnessisary pressure on the bond at the hairline.
The other thing is i make sure the water isn't running too hot when going directly onto the piece so i don't soften the bond.

and when i get out of the shower, i just make sure i pat the piece down, rather than freely rub the towel all over it.

That's how i do it anyway