The Best trainer in Marshall/Warrenton VA!!! Crystal is a certified dog trainer who focuses on onsite dog training(she comes to you) which is awesome for focusing on issues around the home, ranch or farm and provides custom one on one training at your home or local dog park for around the same price as the chain store. She guarantees her training as well. if she trains your dog and the problem returns she will retrain both the animal and the owner again for free.