Empty layers can be created in the Layers panel or from the Layer menu. Layers are created above the currently selected layer. Once created, layers can be renamed for easy identification.
Do one of the following:
With no layers selected, paint on your page with the Paint Brush Tool.
By default, the Assistant will create a new layer to accommodate your paint strokes.
Do one of the following:
The will take you to the layer lower down the stack, whereas + switches to the layer higher up.
You can enable Ask for name when creating Layers and Groups setting to be prompted to name them upon creation. This is found in the Settings (or Preferences)>User Interface section.
Do one of the following:
The latter can also be performed between documents.