Darken Some More
Want to deepen the whole scene, so a different contrast (than the foundation) does the most attractive job. But I want to push a bit deeper still...
Each of these steps is a layer (or two), representing 1) a very easy decision to choose the blending mode, 2) a relatively easy decision for choosing the best contrast to do it with, and 3) a potentially more laborious decision to nail the right opacity.