While many problems can be fixed in software after capture, focus or sharp focus, is not one of them. Focus must be obtained at the point of image capture as no amount of post-process sharpening can bring an out-of-focus subject into focus. One way to gain better control over your point-of-focus is to separate the focusing action from the exposure reading when you fully depress the shutter button. Most all DSLRs and many point and shoot cameras are capable of separating these two functions. In the case of a DSLR, you can assign the focusing action to one of the other buttons on the back of your camera, known as "Back-button Focusing". This allows you to place your center focus point, which is your most accurate focus point, directly on your subject to obtain sharp focus and then re-compose the shot as desired gaining the proper exposure for the re-composed scene when you depress the shutter button. Not only will you begin to increase the number of sharply focused images you are recording but you will also gain more accurate exposure readings for your scenes. Review your camera manual for instructions on how to set this up on your particular camera then give it a try, it may take a while to get used to this new way of image capture but the results will be much better and more controllable than when both functions were engaged with the shutter button alone.