There are several ways to organise your layers in Photoshop to make them more manageable or to group them together. You can use layer comps or layer folders, OR another option is to use colour coding in your layers palette. This can help to give you a quick visual reminder of layers that are related or should be grouped together.
The shortcut to add a colour to any individual layer is to Right-click (windows) or Control-click (mac) on the Eye icon next to the layer you want to colour-code. A pop-up menu of colours will appear and you can select the colour you want.