My 6 cobra taps were getting to be impossible to differentiate, so I came up with an easy label solution.
Copy pasted images from google image search into a word doc, then resized to be less than 2" wide. This allowed me to laminate them with packing tape. Printed on photo paper then covered with packing tape, hole punched and twist-tied to the tap line.
I don't brew all clones, just used beer names that people could identify the beer's flavor with.