Pushups with your feet up high are tough without getting weights or other objects involved. Start out with your feet on the bottom step (assuming you have stairs in your house, continue moving up the stairs as far as you can go. When you get to the point of being able to do handstand pushups, I would call that pretty difficult. I used to do them in gymnastics while doing a handstand against a wall, but I was also very small then.I've seen people who can do them without any wall assistance. Something I'll probably never achieve.