Tip 1#: Layers
When moving layers/selections with the keyboard arrows hold shift to jump small areas (this helps to move selections quickly)

Tip 2#: Selections
Hold CTRL and click any layer to select the outside of that shape.

Tip 3#: Fonts
Loading a large number of fonts into Windows can slow down Photoshop loading and running - using up valuble RAM. For one-off uses, rather than installing the font on the computer, just open the font file and then open Photoshop. This will allow the font for use only while it's open.

Cheers,