Previously used a sharpie covered in clear nail polish to put my contact details on my boards. That's worked fine but was a bit of a hassle and didn't clean off 100% when I sold a board. This time I got some "Sea-ID" labels (
http://www.sea-id.com) and they look really good! Time will tell, but they are supposed to last as long as a board yet are easy to remove should you need to.
Limited colour combinations but the gold on black blends in reasonably well on my boards while also standing out enough that nobody is going to miss it should I lose one. £4 for one sticker but £1 for duplicates - £2 each for my three seems very reasonable.
