Transitioning from a walk into a lope requires picking up the hands softly, pressing in with the outside leg and clucking calming to the horse. Ensure a smooth transition from a walk to a lope when riding horses for show with helpful advice in this video on riding and caring for horses.
Walk into a lope. What you are looking for is your horse to come walking in nice and quiet, and on a loose rein, and look relaxed. This is the first time the judge sees you and he will form an opinion of you and your horse right from the start. When you go from the walk to the lope, what you want to do is pick our hand up soft, put your outside leg in, and cluck to him, and make sure your horse moves his hip to the inside, to ensure you to get the correct lead.