Good luck with the chart - some kids really will work for those stickers!
I approached potty training my kids just like housebreaking a dog.
If a puppy can learn at 12 wks, surely most humans can learn by the age of 2.5/3.
1) Take the puppy, I mean human to the designated elimination spot (toilet) consistently. It's not 'honey, do you need to go potty???' because the answer will always be 'no, I"d rather keep playing dolls and pee all over myself'. At first, I took the kids every 30 minutes (15-20 for a puppy...) They had to go sit on the potty for at least 2 min every 30 min. Use a kitchen timer, etc to help. If they went potty, they got to get up as soon as finished. If not, they had to sit and try for at least 2 min.
When you are getting results, you can go up on the time until it's every 2 hours, then 3 hours, etc. If they have an accident, go back a step to 1 hour, etc.
2) Wear regular clothes and underwear. I'd just recommend no shoes because nothing says 'yuk' like pee filled shoes... The wet clothes are not comfy at all. Pull ups are just expensive diapers - use them only at night, or if you are going out away from a potty for a length of time etc. Heck, I've pulled the van over on the side of the road more than once when it was 'potty' time - of course, that's easier with boys
3) Reward, reward, reward - I just used praise with all but one of mine, who needed the more concrete chart idea.
4) I did not fuss at the kids when they had an accident, but I didn't say what I hear a lot of people say 'That's OK, you'll get it next time...", ah, no, it WASN'T OK... I would say. "You had an accident didn't you? You need to make sure to get to the potty so that doesn't happen next time." I would say it firmly, but not in a mean or fussing tone. They needed to know that using the potty was NOT an optional thing.
That worked for me - I potty trained 4 and even the slowest one was trained by his 3rd birthday. Took about a week of the really short timer routine. Kids figure out that if the quicker they go in theh potty, the more time between mandatory trips they will get.
As with most parenting issues, CONSISTENCY is the key. LOVING discipline (note, not punishment...) but dicipline - sticking to the plan - goes a long way too. And PATIENCE! Not every kid will take to the potty as fast as another, but that doesn't mean you need to give in, just means it will take longer number of days of very regular mandatory potty visits to get it. Sometimes it is a develpmental thing - but often is just stubbornness - they are too busy playing to be bothered with your potty routine - you just have to keep putting them on there every XX minutes until they figure out that you are more stubborn than they are.
Personally, I think a lot of the 'it's developmental', and 'wait untl they are ready... go back to diapers if it doesn't work' stuff is just advertising for diaper companies. The longer it takes you to potty train, the more $$ in the diaper manufacturer's pocket. T Berry Brazelton is the king of the 'wait until they are ready' bandwagon - and he's also a paid spokesman for Pampers.... I rest my case!
Good luck!
Susan