Pistol squats can take months to master, so take the time to learn that skill before moving on to bosu pistol squats. When you do decide to give bosu pistols a try, be sure to focus on form and execution, not speed. The same as you did with mastering pistol squats. The worst that can happen is that you’ll fall. No big deal. Just get up and try again with as perfect form as possible. And, remember, tighten your core to maintain good balance.