I have as much problem with beginner leads who use no force as with beginner leads who use too much, and invitational leading is not beginner leading. I think this is something that needs individual feedback rather than general guidelines.
Yeah, it's better to talk about individual examples, especially as a beginner. Eventually the more general rules will become clear, but that takes a while. Going through the examples you've used so far:
For a push-spin, don't touch the follower's left hand.
For a wurlitzer, see your previous thead:
http://www.cerocscotland.com/forum/b...wurlitzer.html
For a catapult, see here:
http://www.cerocscotland.com/forum/b...-catapult.html
What problems are you having with right-handed returns?
Take the follower's right wrist with your left hand. Move her right wrist in a circular motion around her waist and let go.
Any other moves that you have trouble conveying?
It is to do with feel, but each move has a different feel, and that can (and should) be taught. If it isn't, ask us, or ask a teacher, or ask someone else.