How do I fuck my boyfriend?

(Hopefully that title got your attention)
So, my boyfriend and I have been talking through some new, super kinky ideas and one of them was to have me fuck him with a strap on. I want to try but I'm always the submissive one, I don't know how to fuck him. It's a new position, new power, everything. And I don't know how much muscle it takes to thrust like that. Thoughts/suggestions?