J.M.
You have gotten a lot of good tips already, but I thought I would throw in a couple that helped me.
We did what both of my daughters still refer to as the "potty beep". This was the timer on the microwave set for 20 minutes to start out with and gradually increasing time the second day. When the beep went off we went to the potty and tried to go, no matter what was going on then they helped me reset the timer again. It helps get the idea of going across and if you go that often it is way less likely an accident can happen.
The other thing we did was use the character underpants. Each morning when we put them on we would talk about keeping Dora, Elmo, Spiderman, etc. happy. I explained it made them sad when they got all wet, but keeping them dry made them happy. Toddlers are very big on pleasing even if it is the character on their underpants. This also led to reinforcing every time they went to the potty that Dora was happy, so it was like praise from that character too.
Good Luck