Originally Posted by Cmike2780

Always frame for the shot you want, because post processing can't solve everything. The rule of thirds is a good method, but I usually take multiple compositions of the same shot. This is what narrows the gap between the pro's and amatures. Back in the day, most of us were limited since we couldn't go through rolls of film like the pro's. With memory cards, you can shoot away without needing a huge payroll. This is something most people can't grasp right away. Your odds of getting the shot greatly improve if you take A LOT of pictures, not just a few. It's gets tiring and it feels like you shouldn't have to, but this is how the pro's get "the shot."

For most moving shots like that fish shot, you need a lot of light or a larger aperture. Use a diffused speedlight, strobe or even a flashlight and you can "freeze" the action with a faster shutter speed. Raising the ISO should be a last resort since it will start to get noisy at ISO 800 and higher.