Children learn by making mistakes…
Try to look past success or failure and instead focus on getting your child to attempt.
More attempts = more learning 
The more they try something the better they should get (over a period of time).
One of the fastest ways to learn is my failing/making mistakes.
With each attempt they fail a little less.
They learn from each mistake and correct it the next time.
The worst thing we can do is let them believe they have failed or succeeded at something and so they may as well not attempt that particular thing again.
Maybe they they are learning to shoot with power…
After a few attempts they see no improvement and give up.
Or, they increase their power, believe that’s enough and stop trying to improve it even more.
Praise the effort, praise the fact they are trying, praise the fact they are attempting to improve and encourage them to continue making attempts.
Don’t worry about the ‘result’, worry about getting them to keep trying no matter what.
