Potty Training

We have not been giving our full attention to potty training until now. I know I am to blame because it is so much easier to just put Luke in a pull-up. I have decided to put him in his "big boy" underwear unless he is sleeping. He has done a pretty good job lately. We have been putting stamps on a potty chart that I made him. He has already earned a new little truck and now we are working up to an ice cream treat!! Does anyone have any other suggestions?? Some days he is so good and willing to sit on the potty and other days he says, "I too busy". Ahh, we'll get there.