Pick the focus point manually
Focus-points on most SLRs, and some of the mirrorless or four thirds cameras, there is an option of selecting what point it uses to focus. Meaning, when you look through the camera and see some flashing dots or squares, those are your focus zones or spots. Make sure it is NOT set for the camera selecting which of those spots are targeted for focusing. When the camera chooses where to focus it can often pick the wrong thing. If you have a subject that is behind something in the foreground the camera will usually pick the closest object, which is not your intention, and you’ll end up with the wrong thing in focus.
Find the setting that allows you to adjust which target focus zone the camera uses to focus. Depending on the camera make and model, that can usually be adjusted with a dial or joy stick on the back of the camera, while you are looking through the view finder. This frees you to choose the most appropriate zone or spot for your subject or scene.
Select the right focus mode
Canon-focus-modes most cameras have a few different types of focus modes. On Canon you’ll see them as Single (One Shot), AI (stands for Artificial Intelligence) Focus and AI Servo. On Nikon the modes are AF-S, AF-C and AF-A. Choose the one that bests fits for the subject you’re photographing.
Single (or AF-S) means that the camera will focus and lock on a single object and will not refocus until you release your finger from the shutter button. AI Servo (AF-C) is for continuous focusing when you have a moving subject. In this mode when you depress the shutter button half way, the camera will continue to focus on the subject as it moves away or towards you. It does not lock focus until you press the button down fully and take the photo. In AI Focus (AF-C) the camera will choose between the previous two based on whether the subject is moving or not.
Set your minimum shutter speed accordingly
Min-shutter-speed there is much debate about this subject in terms of how slow is too slow for hand holding your camera. Some instructors will say 1/60th of a second, I tend to use another rule of thumb which is 1 over the focal length of your lens. So, if you are shooting with a 200mm lens, then 1/200 is how fast you need to be shooting to get rid of blur caused by camera shake. The longer lens you select, the more amplified any movement will become. If you are shooting with a cropped sensor camera, remember that 200mm is now acting like a 350mm so that changes your minimum shutter speed to 1/400. If you use a lens that has image stabilization then you can often stretch it a little bit more, say one or two stops, depending on how steady your hands are. You also want to make sure you are holding your camera in the most stable position with your left hand UNDER the body and lens (sort of cupping it) and both elbows in tight to your body. Then, hold your breath and shoot!