One of the ways I became a great High School shooter was by challenging myself to shoot 10 long shots (3 pointers today) in 1 minute or less. I would do this alone and often. These are uncontested shots so one should be able to hit between 4-6 everytime. .
Notice how bad my first shot was (rushed & off balance) and I missed my second one. Never fear misses because as long as mechanics are good and confidence is high, the makes will come. After 3 straight swishes, I knew I was going to be fine. Getting your own rebound is crucial as if you miss badly and need to run far to get the ball, there is even more pressure to get in the 10 shots. .
I finished with making 5 out of 9 in 50 seconds as I counted incorrectly, but still was over 50%. These kind of extra drills can make the difference between average and above average. .
Finally, one always wants to end well, thus putting my finger up (confident) before shot #9.