What are some tips for mounting a horse the first time?

Mounting a horse for the first time is one of the highest-stakes moments in horsemanship precisely because it is the moment where the horse's preparation is tested against reality rather than against training scenarios, and where any gap between what the horse was prepared for and what he actually experiences in the mounting moment can produce consequences ranging from a mild spook to a serious wreck. The tips that make a first mounting consistently safe and positive require patient systematic execution rather than the rushed optimistic approach that produces many of the mounting accidents that experienced horsemen have witnessed in their careers. Preparation is the investment that makes the mounting itself almost anticlimactic when it is done correctly. A horse that is genuinely ready to be mounted for the first time has been thoroughly desensitized to everything that mounting involves — the movement of a person above him, weight applied progressively to the stirrup, the flap of the stirrup leather against his side, the creak of the saddle as weight shifts in it, and the feel of leg pressure applied from above. Lean across the saddle with full body weight from both sides. Apply stirrup pressure progressively from the mounting block until the horse stands completely still through the full weight of the rider leaning heavily into the stirrup. Swing a leg over slowly from the mounting block and rest your leg gently across the saddle before swinging back down. Each of these preparatory steps is a first mounting in miniature. The mounting block is not optional for the first mounting regardless of the rider's physical capability to mount from the ground. The mounting block removes the lateral torque of a ground mount and allows the mounting to happen slowly and in stages rather than as a single committed swing that cannot be aborted if the horse begins to react. Position the mounting block so that you can pause at each stage of the mounting — stirrup foot in, weight in the stirrup, body across the saddle, leg beginning to swing over — rather than completing the entire mounting in a continuous committed motion. Choose the first mounting environment carefully. An enclosed safe area — a round pen if available, or a small arena with solid fencing — is significantly preferable to an open space where a horse that bolts has unlimited room to run. Have a capable ground person present who can observe the horse's body language and assist if anything goes wrong. Once fully mounted, sit quietly for a moment before asking the horse to move — allow him to process the weight and position of the rider before adding the additional complexity of the aids. The first ride should be brief, quiet, and completely successful rather than ambitious, and it should end while the horse is calm and willing. The horse that has a first mounting experience that is calm, positive, and completely within his current preparation level has had the single most important experience in his entire under-saddle career.