The rule that I have always used with trick training is you need to use something that is out of this world good~so they will look forward to earning their treat

I have used a lot of different things to catch their attention (works great for pictures too) tiny pieces of cheese, honey nut cheerios, frozen veggies, tiny pieces of turkey lunch meat. When I had the personal trainer coming to the house when Pebbles was very small she always wanted a little chicken but that was the only time I ever used chicken to train but it worked very well~of course

When they are very small you should only work on training for a few minutes at a time so none of these treat will be a meal anyway. When they start to loose attention, get tired, or don't want to full cooperate you should stop. You will see how well he will pay attention when they know this is the only time they will get the wonderful treat. I would also suggest that you start to train to sit before you let him out the door for potty. My 3 will sit and stay when I open the door to go out and I taught this with a treat as well. The idea is that eventually you will no longer need to give a treat for every trick and then they will just do the trick on command. I know this is way more information that you originally asked for but I have to say that I have seen excellent result by using these ideas and thought I would just pass it along to whom might listen to me babble

Doodlebug had so many trick down when he was a very small puppy, people would just crack up to see him "perform". He was probably 14 weeks and he knew sit, down, roll over, give paw all on
hand commands. Pebbles who just about drove me crazy saw all the great treats he was getting for his tricks that she finaly decided to cooperate too. Bogey who is from a shelter and was a little over a year learned from watching the other 2~but he's a little piggie and will do anything for food

He took a little longer to catch on but he was not socialized when he came to me so that came first. He is still learning now almost a year later but now even dances for a treat.