Hello budding astroimagers!
Here are my top ten tips for getting started in astrophotography:
1) LOCATION, LOCATION, LOCATION: As in real estate, location is everything. If you are not lucky enough to already be living in a "dark-sky" area, be sure to find the nearest dark-sky site where light pollution is at its lowest. Dark skies, void of light pollution, not only enable you to see the Milky Way and countless stars, nebulaes and galaxies above you, it also presents the astro imager with the ability to use longer exposure times and therefore be able to absorb as many photons as possible leading to capturing more celestial objects.
2) PRACTICE, PRACTICE, PRACTICE: As with everything else, the more you do it, the more repetition, the better you become. Even basic astrophotography has a learning curve and can be challenging so "repetition" is vital. As you climb up the ladder of difficulty, such as through-the-telescope imaging, everything becomes more challenging. There is no replacement for hands-on practice!
3) Before an astro shoot, be sure all your lenses are cleaned both on the front and rear elements. It is also a good idea to clean your camera's viewfinder and LCD screen.
4) Be sure you are using a lightweight but sturdy tripod such as those made from carbon fiber. You may find yourself shooting in windy conditions or you may be using a long lens and other accessories that add on weight to your setup. The tripod's mount is vital to stability just as a telescope's mount is. Stability is even more crucial in night-sky photography because of the long exposure times and extreme low-light conditions. Always be sure to get a mount that is rated for weight bearing that is more then your current setup.
5) ALWAYS use a red light to protect not only your night vision but other group member's night vision. If you do not want to get stoned "by rocks that is" then never turn on a white light while pursuing amateur astronomy and/or astrophotography.
6) For stability, the second best friend you have after the sturdy tripod is a remote shutter release that fires your shutter electronically and therefore avoiding camera movement which will blur your images. You can also fire your shutter wirelessly.
7) Your workhorse lenses for celestial photography range in focal length between 4.5 mm and 75mm, especially if you are pursuing basic, camera-on-tripod wide-field astroimaging. For lunar photography off a tripod, telephoto and super-telephoto lenses are then used or you can just use your telescope with methods known as prime-focus, eye-piece projection and webcam imaging.
8) With camera-on-tripod wide-field astroimaging, try to connect the celestial sky with an iconic landscape subject such as "delicate arch", "Devil's Tower", "The Acropolis" in Greece or the "Pantheon" in Rome. This is what we call "Earth and Sky connection" and not only does it "bam" up your photo's composition but it also makes it more marketable.
9) Be sure to double up on everything. You will be shooting in extreme conditions such as cold temps, wind, extreme low-light, humidity, and dew. It is vital that you bring an extra memory card, a fully-charged battery, spare camera, remote shutter release and maybe even a spare tripod.
10) Take lots of images because "digital" allows you to and be sure to "Bracket" your images. Do not put all your eggs in one basket and this is especially important in this unique, often challenging and specialized form of photography known as astrophotography.