I would always do Simon says, and lots of around the world, touch your toes, touch the pony's tail, touch their ears, hands on head etc, gets them comfortable with moving around on horse and helps balance
Oh my gosh! My teacher always did red light green light! I loved it! Green was canter, yellow was trot, and red was stop! It was really fun and me and my lesson mates would compete, while our training was saying the colors!
I use games to teach basic skills. Like pole bending to encourage steering skills, groom box relay race to mix horse management and encouraging to use your legs more to control the horse, putting jumps in between games to keep their interest ect.
You could also do blind folded lesson on a lunge line! Really get them to feel their seat and if you do it over a jump it teaches them not to overcompensate or overly lean foreward putting the horse off balance on a jump. All good things to remember! Get them using that body. Wish someone did that with me when I was young! Need it now let