When my oldest was potty training, nothing was working consistently. We tried stickers, candy, screen time. She was over it pretty quickly. One day I spontaneously started throwing little things in a basket such as party favors, happy meal toys, stickers, candy, temporary tattoos. I called it a surprise basket and let her pick something each time she went. This made all the difference! I kept it going with my younger kids too.
One year, my kids each had electronics they wanted. So they spent the summer earning them. I rewarded them with marbles in their jars and when they filled up their jar, they got their electronics.
Generally though, I’m not big on reward systems. I am more in the “when x is done, you can do y” camp. So, if you get your room clean by 1:00, we will go to the movie. I would wait to ask my kids to do something until I had leverage.
I am an elementary teacher and only give our school-wide reward tickets for above and beyond behavior - not for standing quietly in line.