Apply the things you know. Don’t assume you’ll do it right. (Practice!)
There’s so much to know about photography. The problem I run into sometimes is overconfidence. I went on a photowalk with a long zoom lens recently, and I hadn’t used glass longer than 85mm in a very long time. I was shooting at 400mm. In principle, I know that if your’e shooting hand-held, the longer the zoom, the faster the shutter speed you should use. I know that in my head, but I clearly didn’t apply that knowledge while shooting. And of course, I didn’t have a tripod or monopod on the shoot. On the camera’s LCD, my pictures looked okay, but once I got them on my computer, I could see just how shaky almost every single picture was.