If you are anything like me, you hate having to lug a tripod around, a hate which is only outmatched by your disdain for unstrapping it, setting it up, and packing it up again. If you are going to shoot handheld, though, you need to have careful technique and awareness to ensure you still come away with sharp images. This excellent video tutorial discusses some of the common reasons why photographers end up with soft images when shooting handheld and what you can do to fix those mistakes.
Coming to you from Mark Denney, this great video tutorial discusses how to ensure you get sharp images when shooting handheld. By far, the most common reason I see photographers coming home with soft images in these cases is because they try to keep their ISO too low for the shutter speed needed for the subject motion or focal length they are using. Of course, a lower ISO generally leads to better image quality, but with the high-ISO capabilities of modern cameras and the incredible things noise reduction software can do, you shouldn't be afraid to crank that ISO when necessary. Remember that a sharp but noisy photo is always more desirable than a blurry one. Check out the video above for the full rundown from Denney.
The sharpest lens in the world is a good tripod.
I find that in addition to holding one’s elbows in and the viewfinder against one’s face, holding the lens at the distal end (or, better, the lens hood) helps, particularly for longer and heavier lenses.