Another good thing to do is read the manual.

Remember that instruction manual that come with your camera? The one you promptly stuffed in a drawer without bothering to read? Go get it. Then sit down and spend a hour reading every bit of information inside it. I know manuals are deadly boring, but has lots of info that may help you take better photos.
After your initial read through drag it out every so often and take another pass at it. You’ll probably discover the answer to some problem that’s been plaguing your photo or be reminded of some option that you may have forgot was available. In fact reading the manual has to be one of the easiest ways to get better performance out of your camera.