One of the most common complaints that people have about their photographs is that the images should be clearer or sharper. Pictures that look good at small sizes can be disappointing when enlarged to 8" x 10" or even 5" x 7" if the image is not sharp. There are several factors that affect the sharpness of a photograph: the lens, the camera handling technique of the photographer, and the speed of the film.
The quality of the lens will affect the sharpness of the photograph but proper care and cleaning of your lens will help achieve the best resolution that the lens is capable of. Keep the front, back surface of your lens clean. Always be very careful when cleaning lenses. Never touch the glass with your fingers. First blow on the lens to remove any loose partials, then gently clean the lens with lens cleaning tissue and lens cleaning fluid (A clean 100% cotton cloth will also work). Never use a handkerchief or regular tissue to clean your lens. Keep a lens cap on your lens at all times when not in use, this both protects your lens and helps keep it clean.
Camera movement is another cause of pictures that are not sharp. Make sure you are perfectly still. Hold the camera steady and trip the shutter gently. Brace yourself by holding your elbows down against your body. If you still don't get good results, Use a tripod and compare your results to handheld shots. This will help you determine if unsteady hands are your problem.
Film speed can also affect the impression of sharpness. The faster the film, the larger the grain. Large grain size can cause an otherwise sharp photograph to appear fuzzy. This will be particularly apparent in enlargements. For best results, use the slowest speed film that will work for the lighting conditions present.
Watch the background... It's important to use a background that contrasts with the subjects to prevent the subject from getting "lost." Also, avoid overly busy backgrounds, such as telephone poles, trees and other things that may appear to be growing from someone's head.