Hi A.,
When my older two kids were little, I found that a usually good incentive for them to behave was offering them a "reward" of sorts when we got there, and making sure they understood that if they misbehaved in any way, I would give it to the cashier to keep when we paid. It may seem mean, but I'd let them pick the thing and hold the thing, but I totally followed through with that consequence if I needed to. Rarely did I ever have to give the thing to the cashier to keep, but when I did, they remembered it next time, and we didn't have a problem. The ONE time I had a major problem with this method, was my son was acting particularly bad in the store, and when I took it from him and went to hand it to the cashier, he threw a majorly embarrassing hissy, and whaled me one right upside the head, so hard that I literally saw stars. Some people don't advocate spanking, but there were instances I used it, and he certainly got one for that when we got to the car. He never did that again.
With my youngest, I used the counting method. If she was doing something I didn't want her doing, I started counting. I never got past 5, and to this day, if I start to count, she moves FAST!
To use the counting method, you have to come up with a consequence for if/when you get to your number, and be prepared to follow through with it, and consistently.
You will get alot of answers to your question. I'd say you have to find the one that will work for you and your daughter(maybe a combo of methods), but with any of them, the key to its success is to be consistent and definately follow through.
Good luck.
K. W