I've never used playlists as timers. When incall I played whatever I fancied, sometimes clients would make requests, or if I knew such and such liked a particular artist or style I'd put that on.
When outcall which is the majority of my current business, things are a little different. I do have a regular who likes me to bring music, so I've bought a little tin box speaker which I can attach my ipod to which fits easily into my bag. Most of my bookings don't have anything in the background, sometimes client's music or TV. Once I got used to it I've been fine with nothing in the background, in fact I quite like it.