I have had a Brother P Touch label printer for years. I don't think that they sell my model any longer and I expect you can find a cheaper equivalent to this one. It's very simple to use and has a built-in cutter and gizmo to separate the label from the backing tape.
I use it for labeling all sorts of things, such as files and storage boxes. It's great for labeling wall warts. Most of us have drawers full of rechargeable electronic items, which come with their own wall wart. If you don't label the plug it can be almost impossible to work out which plug you should use to power/recharge a particular bit of electronics.