I make toothbrushing a game when they are little so this way they associate the toothbrush with fun. I will play a little with them until they are mouthing the toothbrush, wiggle it around in their mouth a bit and then take it away.
After they are comfortable with it, in between play I will pick one up, brush one side of the mouth and then resume play and repeat until I have brushed all of their teeth. This method takes a little longer but they are happy about it and have nice pearly whites.
The only downside is if they ever find a toothbrush left unattended it is one high prize!
