In order to become a more well-rounded hockey player you have to constantly improve your skill set. One major skill set to improve on is your stickhandling. Becoming a better stick handler allows you to create more time & space on the ice and open up new opportunities for yourself and teammates.
To be a complete stick handler, you need more than just soft, quick hands. In today's faced pace game you need to have quick feet and control & agility with the puck. Looking at the best stick handlers in the game like Patrick Kane, Ryan Getzlaf, and Steven Stamkos, they can stop on a dime and change directions with the puck at any moment. That's why these players rarely get hit and are able to dance around defenders in a split second. You want to be able to move sideways as quick and easily as you can move straight ahead; and doing this while never leaving the puck behind.
Stick handling with a tennis ball is a great way to help develop so many of the stick-handling skills required to have excellent puck control. It's actually harder than handling a puck because the balls bounce, which requires you to have a good touch.
Once you are comfortable controlling the ball off ice, it is time to bring these skills to on the ice and with a puck. You want to have quick feet, and be up on the edges of your skates, while still keeping control of the puck. Set an obstacle course up and go through it faster and faster each time while keeping control. Make sure to place your obstacles, stagger them, then go at it full speed while keeping control.