I am still in the process of training my daughter. She is 26 months old. She started showing an interest in the spring, and would carefully watch what I was doing, and I would explain the whole process, from pulling down pants to flushing and washing hands. Then she started grabbing herself when she went in her diaper and would holler "potty!" So I'd ask her if she wanted to sit on the potty, and she'd say yes, so then I would take her through the whole process.
I do childcare once a week at a church, and there were several kids that didn't want to go on the potty. It's a regular size potty, but is low to the ground. So I really wanted my daughter to not be scared of big potties. I got a portable seat that fits on top of the regular seat and has handles on the side, and she was comfortable with that. I did borrow a small individual potty, but she never showed any interest in it.
In the summer was the first time she actually went in the potty, and we really praised her. There were days she showed sitting on the potty, and other days she wanted nothing to do with it. Since I was newly pregnant, I was so tired and nauseas that I didn't press the issue. For her 2nd birthday, my mother-in-law bought her a bunch of small horse stickers (my daughter LOVES horses!) and said they were for a potty chart, and she also bought a bunch of cloth training pants.
I made a graph chart on fun paper and taped it to the bathroom wall, and that has been the best motivation for her! She knows she gets a sticker if she pees or poops in the potty, but not if she goes in her diaper, or if she just toots while on the potty. Since I'm pregnant, I'm going to the bathroom every hour or two, so I would invite her in. Sometimes she'd say no at first, and then change her mind. Or if she didn't want to, I'd remind her if she went in the potty she could put a sticker on the chart. Since she LOVES doing that and loves showing off the stickers on the chart, she would agree. On her own, she learned how to release whatever was in her bladder. And now she can tell when she has to go poop, and she doesn't want to get off the potty until she's done. (So there are times she sits on there close to 30 min..... it gets boring, but it's worth the wait to see her excitement and see how proud she is that she listened to her body and went in the potty!)
First thing in the morning, after naps, and after meals we take her to the potty. And we check with her throughout the day. She's at the point now where she's waking up with a dry diaper, and keeps it dry all day. There are a few accidents here and there, but we still praise and encourage her.
So that's what's working for us, and I know that lots of moms will give other great advice.