Mechanics

[wisref2]

No such thing as a reach-in foul so remove the words from your vocabulary. It will help you in the long run. Which foul it is depends on what happens. Was there contact with the arm against the body? Then it's illegal use of hands. Did the arm contact the body and hold the dribbler from his/her path? Then it's a hold. Did the reach cause body contact? Then it's a push or a block.

For the hook - I signal a hold and verbally say hooking. If I really have to sell it, I'll give the hold followed by a hooking motion, but not very often.