Learn by Teaching

Here's how to quickly learn what you've been taught at your tennis lessons. Teach it to others. When you learn the use of the opposite hand, for example, you need to immediately find a partner that has NEVER been exposed to that tip. Teach them the use of the opposite hand, and then ensure they understand it; the only way to teach this tip, or any tip in tennis properly, is to first understand it, and finally, to teach it to others!