Below is a video of Vasyl Lomachenko practicing punching accuracy with a tennis ball and hat. It’s a fun exercise!
How I made my boxing accuracy toy:
I used a knife to poke holes directly opposite of each other in a tennis ball, then pushed through the two holes a straightened out wire from a coat hanger, wrapped 5/8″ elastic chord (I got mine at Walmart in the arts and crafts section) around the wire end sticking out of the ball, and then pulled the wire back out with the chord to get the chord all the way through the ball. Then I just knotted off the one end, and tied the other end to my hat. Standing up straight, with the hat on, the ball should be in line with your belly button.
It’s a fun little interesting exercise that is very effective in increasing punching accuracy because it requires you to constantly improve hand-eye coordination in order to get better at it. The more you do it, the more rhythm you will develop. And the more rhythm you develop, the more fun you can have with this exercise!