Photoshop tips
Quickly Copy Layer Masks
You can quickly copy Layer Mask between Layers just by holding [Alt + Ctrl] and dragging the mask between the Layers in the Layers Palette [F7]. To move a Layer Mask, just drag the mask without pressing any modifier keys. When dragging to a Layer with an existing mask, you’ll get prompted to “Replace Layer Mask?”.
Resize a layer
Edit / Free Transform
Or rather, CTRL-T.
Copy merged
Copies all layers, pretty handy
Cropping a certain area
Magic wand the colour rectangle area and then do a copy merged