What are the best groundwork exercises for beginners?

Beginner groundwork should focus on the four responses every horse needs to give a handler reliably before mounted work becomes safe and productive: move forward, stop, back up, and yield the hindquarters. These are not tricks or advanced techniques — they are the basic vocabulary between horse and handler, and everything else builds on them. Start with leading correctly: the horse should walk beside you with its head at your shoulder, neither lagging behind nor crowding ahead. If the horse gets ahead, stop and back it up to the correct position. If it lags, a cluck and a swing of the lead rope end toward the hindquarters encourages it forward. From there, teach a clean halt: stop your feet, say whoa, and wait for the horse to stop without pulling on the lead. The horse should stop when you stop, not two steps later. Yielding the hindquarters — stepping the hind feet away from pressure applied by your hand or the end of the lead rope near the hip — is the most important single exercise for establishing respect and control, because a horse whose hindquarters you control cannot fully flee or kick. Backing is taught with steady finger-walking pressure on the lead rope or chest pressure, releasing the instant the horse offers a step back. Each of these exercises should be clean and responsive at a walk before you add energy, distance, or more advanced movements.