When you are shooting a photo of someone, make sure that you are close to them to maximize the quality of the details on their face. This is very important, as you will want to capture every aspect of their expression to help to personalize the photos that you take.
Take successive photos of your subject if there is a chance that it might move. Certain subjects, such as wild animals, won't just wait patiently for you to take your photo. In this case, take one shot quickly so that you have something to work with. Then, if the subject hasn't moved, take more shots with better positioning and composition.
If you are having difficulty holding your camera straight, purchase a tripod. A tripod will go a long way in helping to keep your camera in place, so you can focus on other variables other than balance. Tripods work great if you are in the wilderness or on an uneven terrain.