Dog Biting Problem

I've had Lily and Sandy for several weeks and the dog training tricks are working for the most part. Sandy has finally learned not to go on the bathroom rug and uses the doggie door like a pro. She has also stopped chewing shoes and only chews things I give her. I am very pleased with the dog training progress we are making with Sandy. Lily is still whining but is getting better. She only whines in the morning when she hasn't seen me and when I drive into the garage. The big challenge I have now is a biting problem. Sandy is very aggressive when she plays and biting is a big part of her playing routine. Lily bites a little when I first greet her after being gone from the house but it is more excitement and stops as soon as I pet her. Because Sandy is the youngest of my three dogs, she has the most energy. She runs a lot in the backyard and is the most playful. Other than the biting problem, she has done the best in terms of dog training.

Please share any dog training tricks you have found helpful in stopping your dog from biting.