Warning: this rambles a lot.
I was surprised about when I wanted to be explicit and when I didn't when writing Days of Becoming
. The hottest and most explicit scenes were definitely those at the beginnings of relationships (either Bobby/Lance or Bobby/John). And as Bobby and John were working through the first winter of being together, I got them into interesting and explicit situations. I think I needed the reality of the newness of sex to be on the page. There is this big jump from the imaginings of sex to its mechanics, and in the mechanics you can play with the abandon, the awkwardness, the new language of physical communication — all those levels. I'm reminded of Bobby figuring out how give a blowjob and also the first time he really looks at someone's asshole, but also the guilt/excitement of shooting cum on the clean towels in the linen closet.
You'll notice, however, that the sex became more "off the page" later. There is a lot of sexual tension in the hotel room in San Fran, but the sex (or at least its description) is more perfunctory. The last sex scene of the book is dialogue-only and ends with the request to be fucked. I'm not entirely sure why this is. There is a more explicit draft of that last scene, and it didn't work as well. Maybe because we already know how they insert tab A in slot B.
And violence... hmm. I like writing action. I think I realized during the scene at the Turcott clinic that the subjective experience of action would be one of chaos and that the difference between a seasoned vet and a rookie would be how well he/she can sort out patterns within the chaos. From there, it was like writing a comic book action scene, but from inside one character's reality rather than with the objective frame of the panel or camera. Powers, debris, screams — all fun to manage.
Truly, the most violent scenes are really ones about fear — I'm thinking of Mike about to die at the hands of Friend of Humanity in the gym at his hs, and Bobby being dragged to the punishment rooms in the camp. In those scenes, the emotional violence is pitched high. In the latter, as with some of my sex scenes, that was more important than actually seeing the acts.