My mom always did it over the 4th of july weekend when me and my two siblings were young. Give her a prize or candy every time she uses it, and that should encourage her to use it every time she has to use the bathroom. Maybe you should start her off on a dora or disney princess potty that is about foot or two off the ground. I am 13, i taught my 3 year-old cousin how to use the bathroom by using those techniques, and she learned pretty quick! Sorry that this is really long! :)
Me and her showed one of her baby dolls how to use the potty then rewarded the baby doll when she went, she associated with it to herself and just started using it, it only took like a week and she was potty trained good luck
The best way is to buy a potty that is comfortable and let her personalize it with ribbons, stickers and anything else she might like. Then, you can demonstrate to her how to use it by using her favorite toy or doll which she can easily imitate.
Let her watch you and take her with you when you have to go. Tell her this is what big girls do. Girls really idolize their moms. Then praise her when she wants to even sit on a potty. oh and do NOT use candy!!! she would expect it every single time.
Prizes. Or with my son my preschool and I just put him in underwear and then when he wet himself or pooped himself he didn't like the feeling so he started to use the toilet. I also grabbed a new trash bag and put it in the trashcan and had my son "trash" the rest of his diapers and pull ups. So he got the concept that underwear is all he has. But after he "trashed" the diapers and pull ups I took them out the trash to save for traveling to long destinations. :) hope this helps and good luck!