Been there, done it, got the T-shirts and photos to prove it.
- Wash your hair you dirty bastards. Freshly washed hair is the easiest stuff to knot in the world. Just wash it with plain, unscented soap then don't condition it, it will be a dread-making paradise.
- Swim in the sea as often as possible, don't rinse the water out. Salt-water hair is second only to just-washed hair in terms of knotting potential.
- Section off a square inch or so of hair, fire a rubber band around the base of it, get a pet brush and tease the hell out of it back towards the base. This is called back-combing, this makes knots, knots are good.
- Surfboard wax? Fucks sake, they make dreadlock wax for a reason. Rub dreadlock wax into your freshly made baby dread, then fire another rubber band around the tip.
- Continue washing it at least once a week, swimming in the ocean and fiddling with / rolling them whenever you have a free hand. In a few months they'll be locked in and awesome.
- Have good mates. It's going to take a couple of your untrained monkey-friends at least a day, a full, serious 8 hours of work to do your whole head. You're going to want to ply them with food, booze and anything else they demand or they're gonna leave you looking like a pillock with half a head of baby dreads.
- If you have to ask how much a hairdresser will charge to do them, you can't afford it.