My 3 year old son was potty trained and then regressed, so wew're having to start from the beginning. What worked for us was using a potty chair in the beginning. That way he coul shave his feet in the ground and felt safer. It's best to have kids start by sitting down rather than standing up, since it can be tricky to differentiate between the need to pee or the need to poop.We also used candy rewards for each successful pee or poop in the potty chair. For peeing, we give one small candy, like one m&m, and for poop we give a bigger candy like a small peanut butter cup or a small lollipop. And of course, giving lots of praise with each successful attempt helped a lot to encourage progress.make sure you don't scold or punish for accidents, as that kind of negative attention only reinforces the bad habit. Until your son gets the hang of going in a potty chair (I like the Baby Bjorn or Prince Lionheart chairs) keep him in training pants. They are absorbent, so you won't be cleaning up messes, but they look like underwear, which make them a nice transition. I like the Earth's Best training Because because they are Eco-friendly. They are also good to use overnight.