One particularly clever way to get sharper images out of a long term photography exposure is to use a good solid tripod. Tripods are a time-honored way of getting a still shot devoid of the shaking human hands do, a method dating back to the beginning of photographic technology. Holding a camera steady is rarely enough for a long exposure, and when you need the camera to hold still, a tripod remains the favorite answer of photographers everywhere. However, simply getting the cheapest tripod you can find is a bad idea as these tripods tend to be constructed in a way that causes them to shake far too much. Getting a good, solid quality tripod leads to a stiller, less blurry shot.
Using a remote shutter release system is a good idea as well. This is because simply pressing the button to start the long exposure photography process can also shake up a camera. Because any sort of movement becomes increasingly noticeable when the length of the exposure grows, still these movements become ever more paramount to getting the best shot possible. One way to handle this problem is to delay the camera for two seconds on the timer, after which the camera will likely be a lot stiller. Alternatively, one can get a remote shutter release. These devices are typically connected to the camera via a wire or a wireless connection and are also known as remote cable release. They are fairly small and cheap, making them well within the range of most photographers.
Another good idea is to use the manual focus. Autofocus is a great time saver for most quick exposure shots, but a longer term shot tends to actually cause autofocus systems to blur the shot instead of sharpen it. This is particularly true of low light shot where the system oftentimes has a hard time finding something to focus on. In a similar vein, ND filters will often have the same issues as well. Using the manual focus systems to focus your shot is a great idea for getting a less blurry shot over the course of a long exposure. Using a flashlight for focus is also an option, but one should use the flashlight, then lock their focus to get the maximum effect out of this technique. Sometimes it really is best to use less technology.
Finally, a good idea when using a DSLR camera is to lock the mirror. These cameras have a mirror that reflects images from the lens directly into the viewfinder and tends to move a bit when shifting about inside the camera to get the best shot. However, there are actual vibrations involved here and that tends to blur the shots of a DSLR camera even under ideal conditions. To deal with these problems, it is advisable to use the viewfinder first, then lock the mirror in place before setting the shot to begin the long exposure. Taken together, these tips should lead to sharpening shots despite the longer exposures.