My son was 2 1/2 when I said "Hey Isaac, you are going to wear "big boy underwear" now, I want you to go pee pee and poop in the potty like Mommy and Daddy does." By this time he had been waking up every morning and from naps with a dry diaper. Within 3 days we were accident free. He still, to this day, has only peed in the bed once. This was after going to the circus. He was exausted and had over indulged in snacks and drinks on his night out.
It is not really the child that you have to train. It is you. For the first 2-3 weeks you have to remember to take them strait to the toilet after naps and when waking up from the night. You know your childs schedule. What time during the day does he usually have a bowl movement? Keep that in mind, and remember to remind him to go sit on the potty around that time.
Praise is always good for a child, but using a toilet is just an expected human behavior. Trust me, doing a poo poo dance once a day for 6 months is going to get old. A piece of candy with every time they visit the toilet equals a mouth full of cavities. Just a good ol' "good job, Buster" and a pat on the back will do the trick. He will be proud, if he sees that you are proud.
Some extra things to remember:
No drinks at least 1 1/2 hour before bedtime.
Kids shouldn't have a cup of juice or milk all the time just to sip on. This is one of my pet peeves. It totally ruins thier appetite and their teeth!! Plus makes toilet training impossible. They will be wearing (another of my pet peeves) a pull-up until they are in the first grade. A child with no physical reason and at the right mental age, should have no problems potty training. If it seems to be too difficult, there is probably something wrong with the equation.
Keep the use of the pull up to a minimum....like only at night or for long car trips. The pull up is a daiper, plain and simple....it is really just a crutch.