If you will be using binoculars for astronomy viewing, here are some accessories to make your star-gazing sessions more enjoyable:
Essential Accessories for Binoculars
Tripod - no matter how lightweight your binoculars are, your arms will get tired. Binocular shake can quickly end an astronomy viewing session. Any good-quality camera tripod should be adequate, - just remember to get a tripod that is sturdy and won't shake. Don't skimp here, be prepared to spend at least $50 for a decent tripod.
Binocular "L" adapter - you will need an adapter to mount your binoculars to a tripod. Make sure you buy binoculars that have a threaded hole in front to screw in the adapter. Adapters cost about $10.
Nice-to-Have Accessories for Binoculars
Parallelogram mount - this mount fits on your tripod and allows you to retain a comfortable stance and position when viewing. The parallelogram mount consists of parallel rods and pivots that move the binoculars to whatever height and angle you want for viewing. These can really reduce arm, neck and shoulder strain.
Mirror mount - this mount can also fit on your tripod and consists of a high-quality flat mirror that reflects the night sky back at your binoculars. The binoculars are pointed down at the mirror and the image is reflected back up. Like the parallelogram mount, a mirror mount allows you to retain a comfortable stance for viewing.
Solar filters - solar filters (either the Mylar or glass type) fit on each lens of your binoculars for safe, direct viewing of sunspots and other solar features.