The actual words you use will mean nothing - but the tone is all important. Food, carefully used, is a great motivator for many greedy pups. But make him earn his titbits. Some people think that it is good enough just to throw food at a dog. It must have a meaning for the dog or it is wasted.
Toys are good.
Have a special toy that the pup likes and keep it only for training sessions. Produce the toy and ask him to watch. If he gives you his full attention for a second or two, break off and play. Try for another second the next time and gradually build up. Don't ever be so predictable that your pup knows exactly what you are going to do next.