I have only trained girls, my 3 daughters back in the l980s and one granddaughter last September. With my daughters, I used Toilet Training in Less than a Day. It took them 2-3 days but they were all under 2. My neighbor used the same book with her son at 20 months and he did great also.
My daughter had tried praise, stickers, rewards, etc with my granddaughter and had little success. So, she decided to wait. In September, I had my granddaugher stay with me for the weekend. I put her in cotton training panties, took water, snacks, toys and the potty chair out on the patio. I instructed her on what we were going to do. "We want to keep your panties dry. This is what you do..." I showed her how to run to the potty when she needed to go and how to pull up and down her panties. I told her about the rewards of one sticker and one candy (m & m) every time she "tee-tees" in the potty. I kept her filled up with water, and then we played. When she started to "tee-tee", she squealed my name, I grabbed her hand, we ran to the potty, pulled the panties down. Talked about dry panties. She did NOT like those wet ones! We changed her and kept drinking the water. A few minutes later, she started to wet again but ran to the potty and got some of it in the potty. We clapped, danced, got a sticker and a candy. Changed her panties and kept drinking water. By the end of the day, she had several successes and several accidents but it was a good start. The next day we did it all over again, continuing to teach and train. I told her at naptime it was OK to wear a pull-up while she slept but as soon as I heard her stir, I got her up and on the potty.
It was a very consuming job but by the end of the weekend, she was 90% trained with fewer accidents every day. I have heard more than one person say that those pull-ups just don't work well and that was true for her. We only used a small package of M&Ms (less than a $1) and when they were all used up, we discontinued use of those; she was content to wear her "Dora" panties now and keep Dora dry.
For boys, I have heard that you can put a few Cherrios in the potty, tell them to "sink the boat", and they love that. Happy training!