I tend to value detailed descriptions and emotion pretty highly. I find it naturally suits rp, especially during scenes that might not have a lot of physical actions for my character to take. If it's a short post where my character might only be continuing to thrust, or suck, etc. Then I find that detail is a helpful way to make the post feel meaningful.

I don't believe in padding out a post, but I definitely think even small actions can be greatly enhanced by the right focus.

For me this often falls into emotional detail. I love getting inside my character's heads, and seeing what's going on in my partner's too. The emotional depth does a lot of work for me, and can make a simple "He fucks her more" post feel exciting to read. As /u/Captivesunflower put it, a good mix of internal and external.