If you’re rimming a woman, don’t forget her vagina and clitoris and use your fingers to stimulate her there.
Enthusiasm is key! If you aren’t excited to do it, it will show.
Good hygiene is a given, so I’ll not stress that. What I will say is PAY ATTENTION TO YOUR PARTNER. Try a variety of things, be experimental, have fun with it. The cheeks, the pucker, and the interior are sensitive and respond to stimulation