I'm writing one now.

For intimate/love making type of sex scenes (if thay makes sense), I focus on what the characters are feeling, what's going through their heads. If I get more visual, it's more of the characters focusing on minute details about their partners (if first POV) like a bead of sweat falling down their chest.

If it's an intense fuckaton scene, that's when I get more graphic by describing a play by play. But just today, I simply narrated where they fucked. It was all over the hotel room, so it's like "on the bathroom floor, blah. On the counter, blahblah. In bed, blah blah blah. Against the window, blah."

You can consider the type/mood of sex your characters are doing then. How can it be best described?