[alaskayorkie]

Here's what a book called 101 Dog Tricks By Kyra Sundance says:

1. Position your dog in a sit facing you. Use a treat to lure his head up and back while cueing him to "beg." Allow him to nibble the treat from your fist, to entice him to stay in this position. If his hindquarters lift off the floor, lower your treat a little, tell him to sit and tap his bottom down.

2. As your dog's balance improves, move away and use the verbal cue and hand signal (your hand in the position of giving the treat). When he does it for several seconds, toss the treat to your dog. Remember to reward your dog while he is in the correct position, not after he has lowered his front paws.

Troubleshooting:
My dog jumps at the treat: Move slower when positioning your hand. Do not reward your dog if he jumps

My dog stands up on his hind legs: Keep your hand lower, and gently say sit. Hold the treat at face level.