The only 3 tips you need to know out Layers
1. It might seem really obvious, but to work on a layer you need to target it first in the Layers palette. A layer is active when it’s shown as highlighted in the palette.
2. Remember, layers can either be visible or hidden! You can temporarily hide a layer by clicking its visibility eye in the palette. You can’t work on a layer if its visibility eye isn’t showing, but activating it to work on is as simple as clicking again on the visibility eye.
3. The ‘stacking order’ of layers can be changed. You can move a layer to any position within the palette by dragging and dropping it between layers. Those that are higher up have priority over those that are positioned further down the palette.