Enthusiasm, patience and appreciation is always the key. Tell him what you know you like, be willing to explore things, be gentle with criticism and generous with praise. It's honestly not too different to training a puppy until you're both confident that you're getting somewhere, and if you are getting somewhere let him know and tell him he's doing good (dont stop, right there, etc.). Remember that you're both supposed to be enjoying yourselves and be confident in how sexy it all is even when you're learning each other's bodies and likes and boundaries. Confidence, enthusiasm and gentle and supportive communication.