Renaming your layers helps you to see what elements you have added and what layer they are on. If you choose to go back later on to delete a layer, at least you know what layer you ARE deleting. LOL
I have created my tag first, but you can always add your elements and rename them at the same time. For the sake of time, I'm doing it afterward.
This is what my layers box looks like after I have added all of my elements and mask:
Go to the button at the bottom. It has a "tag" with a pencil on it. This is your "Properties" button. Click once and this box pops up.
Do this for every layer you add. This is what my layers box looks like after I rename all layers. (I've expanded it out so you can see it.)