Know Thy Camera

If you care enough about your own photography that you own a camera that has adjustable settings, it is vital that you know how to work it inside and out. You have to be able to get the desired settings without even thinking about it. The reason is this will give you more of a chance to focus on what you're photographing

Every lighting situation is different, every scene is different, and every subject is different. The settings on your camera can only do what they can do. If you're in any particular lighting situation, the first thing is to know what your camera is going to see and make any needed adjustments without having to get out your manual to figure out how to do it. Then you can focus the majority of your creative energy on capturing what you want to capture. Composition, positioning your subject if possible, and if you're photographing a person you have to make a connection with them. If you're trying to do all of this AND fiddle around with your camera settings at the same time, you'll definitely lose something in the picture. 

Know your camera inside and out. Read your manual! Practice!