i am a preschool teacher and have had lots of experience potty training with a variety of different ages. There doesnt seem to be any one particular rule that works, as every child is different, but i will give you what ive got!!!
* The main thing is DO NOT push a child to use the potty if they are not ready. it will only scare them off and delay training time further.
* Get children used to sitting on the potty, eg before and after bath times, before you put a new nappy on etc. you dont even have to ask them to do a wee or anything, just let them sit on it, maybe even with a book. then they will learn that the potty is not a bad place!
* Dont put your child in pullups, in my experience these only serve to confuse the child
* Star charts work. giving sweets is not a good idea as it teaches bad eating habbits, most children are happy just to see their line of stars growing
* If a child repeatedly wets himself, dont get cross. just change him or make him change himself without making eye contact. some children (especially boys for some reason) wet themselves on purpose because it gets a reaction, it gets them attention, even if it is negative attention.
* When you are first potty training, remind your child every 15 minutes, especially if they are doing something fun as they may forget.
* once you decide to potty train, stick with it. dont have pants half the time and nappys the other (apart from night time) as children get confused.
* expect there to be mess, and dont worry about it. it wont last forever!
Good luck! i hope this helps!