What you add to your scenes to make them more interesting?

Possible examples: Plot twists and surprises. Questions and mystery. Imagery (beautiful, exotic, memorable, what?). Neat dialogue.

When I'm just writing, I produce utter garbage, very boring stuff. I don't have much style. So I want to improve that as much as possible.

When I began to investigate how good writers do it, I found myriad things. However, I think I can't quite be sure which findings are important and which are just minor style details.

I have been reading quite many textbooks about writing, but they're nor much help here. They take too much for granted. Some texts about old "pulp writers" have been illuminating, but basically there's not much useful.

I do not need exact advice, but more like what could be good idea to think now and then when my text is going to that "utter drivel" class again.

(If this is hard to understand, sorry, English is not my native language.)