Things to learn about first: Layer masks, clipping masks, adjustment layers. Using softness or hardness of the brush for effect. Using opacity of all layers including adjustment layers for effect. Truly wondrous things can be done with layer masks. The layer blending mode is very key too, although that's a little harder to get comfortable with. Probably my favorite tool is the smudge tool. I use it a lot inside the layer mask. As you get a little more comfortable, gradient maps are amazing!! Overwhelmed yet? I don't use filters a ton, but everyone works differently. Comlodge and I have noted that we each have a very different set of favorite go-to tools. Have fun!