Wiring identification preference?

If you use the factory color coded wires or their look-alike replacement, it's fairly Murphyproof if you have a factory wiring diagram.
Yeah, I’m going to stay to the factory colours, and I have the diagrams, I just feel like and future work would be made easier if I had clear labelling. That way I wouldn’t have to refer to wiring diagrams. My concern is that trying to write on 18 gauge wires is going to be microscopic, and I don’t want big obtrusive tags. My engine bay is already ugly, I’m trying to pretty it up some.

Well, maybe not pretty, but at least a little less cluttered, and I’d like the wiring to not resemble a birds nest.