What to do to start shooting clays?

[g.willikers]

Incorrect, the ONLY way to use aiming with a shotgun is when you are using it as a rifle

Exactly.
It helps a new clay bird shooter to bridge the gap between their accustomed rifles and a shotgun.
And it works with the going away birds on the trap field enough to keep their interest, instead of missing everything.

 

[FITASC]

Hold your foreend with your offhand index finger pointing (and running parallel to the barrel) to the target. Let your eyes and hands move the gun, moving to the target and firing as appropriate.