When I taught my boys it was a lil bit messy the 1st few times but explained they aim like a squirt gun and aim for the hole. They got the hang of it rather quick.
That's how I learned. I can remember my dad and I peeing into the toilet together. Also, that's the way I taught my two boys.I've heard from some guys that their dad just went in front of them to show how it's done. I'm not really comfortable with that and would like to save it as a last resort.