My advice is not to stress over getting kids out of trainer pants too soon. It can have the opposite effect.
I spent a lot of time attending play groups with my sons as I gave up work for 5 years after having them. 99.9 percent of the conversation there was about whose kid could do what. It felt very competitive and mine felt like the slowest in everything. I got bored with competing by the time I had my second son and after a short phase in trainer pants by day I gave up on the big boys pants thing for him until my health visitor reminded me that I needed to retry it when he was about two and a half. She gave me the best solution and said I had to keep him home for the morning just in a t-shirt and pants and give him lots and lots to drink......until the inevitable happened when he would have a gushing pee and feel it running down his legs. After this he would supposedly never wet himself again. It worked and he never once wet the bed either! His brother did it less than 5 times.
