I have found what I think is a good and flexible system. The idea came from our hardware guys at work who in the early days of prototyping machines did their own labelling.
I use MS Publisher for them myself but your favourite graphic or artwork tool will do. Even paint will do it if you are not in a rush. In the example below I created some black labels with silver lettering for an antique look.
step 1 - create your labels - see the attached pdf for some I did for the Taylorcraft
step 2 - reverse the image i.e. make it a mirror image of what you want.
step 3 - print it onto clear film - I used some film designed for laser printing pages of presentations for use on overhead projectors. By printing it in reverse you now have the ink on the back surface of the film so it won't get abraded in use. If you use a laser make sure the film isn't going to get melted by the process. Also, some printer's drivers will have the facility to reverse print so you can miss out step 2.
step 4 - cover the back of the label (rough cut it out of the sheet at this stage if it helps but lave an outline) with self-adhesive aluminium foil tape. I used a wallpaper seam roller to get any wrinkles out. Assuming the tape has clear glue you wont see it.
step 5 - get some double-sided tape and put it on the back of the foil. I use double sided VHB foam tape which is 1mm thick - the sort of stuff the automotive industry uses to attach their badges to cars with - available on EBAY and sticks like s**t!
step 6 - use a scalpel to trim the whole thing to the final size.
You are now left with a self-adhesive custom label that has a tough plastic outer surface and will stick to anything - even my crackle black panel.
If you want black on white you can miss out the aluminium tape and just use white VHB tape. If you want coloured labels you can probably do them on an inkjet. The hardest part of the job is finding the best printer you can to get the densest black on the label.
Just a suggestion anyway............