Mine was interested in her potty for 3 days, and then refused to use it again! I bought the seat that sits on top of the real potty and put it on at all times, along with a really fun step stool. Then, the toughest thing, was making her go every 15 minutes for the first 3-4 days = you have to remember that they are not used to holding it at all, they go whether they have 2 drips or a lot. So, if you take them every 15 minutes, they learn to hold it. THen every 30 minutes. One thing I learned, don't offer physical treats - try mental ones. THere is nothing worse than a child (mine!) that would dribble out 2 drips in her potty every 2 minutes and scream for a skittle, or would go successfully at Target, and then scream for her treat, when I didn't have one. Instead, we set a time for every 15 minutes, and when the timer went off, raced each other to the potty to see who could get there first and pee, and every now and then, I won to keep it exciting for her. Additionally, every time she went, her reward is that to the potty, we sang "Annie peepeed in the potty, peepeed in the potty" to a congo line tune and danced around. She thought this was GREAT, and while embarassing in certain situations, can be done at any time, without worrying about bringing anything special (Target shoppers are very understanding!).
Most importantly, when we went out, we just had to bite the bullet, bring extra clothes and pray. We peed before we left, peed when we got to the store, again halfway through, right before we left and as soon as we got home. Plus, while we were home on our hardwood floors, we roamed in just a shirt. Good luck!
We tried a couple of months off and on, and then it just clicked. One day 50 accidents, the next day all good.
The main ticket is that you HAVE to take them to the bathroom frequently, which is hard to remember. make sure you leave the light on all the time, the seat on and the stool set up, to make for quick speed. Not wearing bottoms for the one that waits until the last minute helps!