Usually when you create an effect, it is the result of several different layers. Let’s say, for instance, that you create a vintage effect that has 3 different layers to it. For me, one of the main advantages of grouping is that you can treat the group as a single adjustment rather than (in this case) 3 separate adjustments.
For demonstration purposes, let’s say you create this vintage effect. It contains a Curves layer, a Brightness/Contrast layer, and a Color Fill layer.
Now let’s say I really like the vintage effect on my photo, but I want to tone the whole effect down a bit. I could go in and adjust the opacity of each individual layer (and there are definitely cases where I DO just want to adjust certain layers – but in this case I want to tone down the effect as a whole), or I could create a group. To do so in this case, I am going to highlight all 3 adjustment layers and hit Ctrl/Cmd+G on my keyboard (for ‘group’). This will put all these layers into a folder.
You can rename the group by double clicking the name and changing it. You can also click the arrow to the left of the folder to expand the layers.
Now if we want to lower the opacity of the entire group (aka the entire effect), we just make sure the group is selected, and we change the opacity.
In addition, you can add a mask to a group if there are areas in your photo you wanted to mask out. (You can read all about masking here).
One other thing – you can also create a group is by clicking the folder icon at the bottom of the Layers palette. (It says “Create a new group” when you hover.)
From there you can drag any of your layers into the group. Happy grouping!! As always, any feedback is much appreciated!