Perhaps the most rewarding work I do is custom inlay work.  It makes such a difference in identifying a personal instrument for musicians!

I use mother of pearl (MOP) mostly, and love the contrast between it and the ebony or rosewood fretboards.  When the light hits the letters they simply glow with the iridescence of the material.
 

I also inlay the walnut accents in the face of my Crossover Ultima thin hollow body jazz model guitars which gives a nice contrast and also accentuates the gold hardware used on the Ultima.  This can be done for any two woods one may choose for their instrument.

Just about any letter font is possible and this is, of course, up to the client.  You do need to keep aware of the possible need to have a fret bisecting a letter if the name is long or you wish to have large letters.
 

I charge $50 per letter for the MOP inlays in a fret board.  Wood inlay is negotiable as not many request this so I don't have a set price schedule.  If you have an idea, feel free to inquire.  I love designing for you!