Photoshop Secret Shortcuts has done a decent job of listing many of the non-menu shortcuts in Photoshop. Here are a few more.
You probably know that command-[ and ] move a layer up and down in the stacking order — and it’s in the menus. However, option-[ and ], while you have a single layer selected, moves your selection (not the layer!) up and down. Handy in recorded actions when you don’t know the name of the layer you want to select.
Another: backslash makes the current layer mask visible as a rubylith, like a Quick Mask.
Two other techniques, not just shortcuts:
When you’re painting a mask, set the Dodge tool to work only on Highlights and the Burn tool to work only on Shadows. That way you can paint straight over edges to sharpen them up, without destroying them.
If you ever need to fill text with your own painting, don’t rasterize the text! Instead, create a new layer above the text and use Layer > Create Clipping Mask. Why Photoshop doesn’t do this for you (instead of admonishing you) I just don’t know.
Plug: I teach a Photoshop Masterclass at Next Byte Charlotte St in Brisbane. You’re welcome to come along. 🙂