As an athlete, honestly, I have to agree with
BuegeSmalls . Yelling at us will get us no where. Yesterday I (finally) got over a mental block of a backhandspring, because my coaches didn't yell at me, they talked to me, and explained to me that every athlete in the gym gets afraid to throw something at times, and one coach explained to me that he still gets scared to throw things sometimes, but you have to just throw anyway, and get over that fear. And about 30 seconds later, I threw it without even realizing I was throwing it.
Honestly, if you just talk to us, listen to our reasons for why we aren't doing something, or why we won't throw a skill, and then put it in a positive perspective for us, while still being firm and stating what you want us to do, we will most likely do it. But just because we say we're scared, doesn't mean that we really don't want to do the skill, and it doesn't mean that we aren't trying, we truly are just scared sometimes. Give lots of drills for tumbling and flying. Drills get the skills, the spot does not. The more confident athletes get when they constantly do drills that they know are going to help them (no matter how hard the drill may be), the more confidence it will actually give them when it comes time to throw it by themselves. (I Speak that from personal experience) I'm not saying don't spot at all, unless you truly don't want to, but the more drills you give the stronger the athletes will become and the easier it will be for athletes to throw skills when the time is right.
Just remember, every athlete progresses and learns differently
remain encouraging, supportive, and positive. :)
Positive Brings Positive, Negative Brings Negative, so after making a correction, if you can enforce something else in a positive way, (i.e., your arms were a little bent in that back handspring, but you jumped a lot more than you did last time.)