How to make sharp images.
By Maurice Blibaum
To start, I use the best lenses I can to suit the job. I shoot with zooms a lot even though I know the primes are a bit sharper. The convenience of the zooms outweighs the benefits of the primes in many cases. Most of my sharpest looking shots are with the Canon 500mm F4 IS or the Canon 100mm Macro.
Probably the most important element to produce sharp photos has to do with camera shake or vibration and the ability to relax when the shot is taken. I exhale and try to mentally and physically relax all my muscles except for my index finger squeezing the shutter button. If your tense, you will flinch, press too hard, vibrate the camera and usually ruin the shot. This is especially important with long lenses and slow shutter speeds as any movement is magnified.
A good sturdy tripod definitely helps with stability and will definitely make sharper images. But don't let that hamper your creativity. I like to shoot hand held a lot as it's definitely less restrictive as far as carrying, with tons more freedom to follow the action. The downside is that you are adding motion that needs to be dampened with good technique and higher shutter speeds. The freedom hand held offers often outweighs the extra stability and weight of a tripod. Not that I condone this sort of thing, but I've shot 2 second waterfall shots hand held with good results by propping the camera against something for stability and not breathing while the shot was being taken. I have no doubt that a tripod would have made the shot better but it's possible to do without.
A properly placed hand on top, over the center of any of the larger lenses will dampen vibrations while on a tripod.
There's more, but the last thing for now is learning proper sharpening techniques in whatever program your using to process your photos. Don't over sharpen as it produces unwanted white halos around objects. Also only sharpen at the finished resolution of your print.