how many songs are you expecting to put on the stick. 
Total = 2016 songs
maybe you could sort your tracks into music styles or alphabetical ...
After excessive experiments and countless rewritings
I've created only 5 folders, one for each general music style. E.g. "Classic rock", "New rock", "Pop", "Oldies" and "Punk"
Each folder contains 100-200 songs (of the respective genre of course).
File names of the songs are begginning with artist's name e.g. "BoneyM-Rasputin.mp3"
This way you can listen continuously to a specific artist.
USB sticks are cheap enough, so consider of using more than one if you think that this is necessary. E.g. I use a second stick for some kind of music that I don't like to play mixed with some others so, I used one stick for Greek music only
(*probably Dazzler throws his hat away right now, he really enjoys this kind of music 
)A few tips for the .mp3
filenames only:
Avoid begginning the artist's name with a "The" or else you may find yourself searching for "The Lemonheads" in "L"
Cut short the artist's name so you can read the song name along while you're searching on the radio screen.
Cheers
