A great way to keep dust and lint from your pocket-bound laser should you carry it with you.
Just cut out a disk-shape from a roll of 3M Packing Tape (NOT the sticky brown stuff that never comes off but the low-tack 3M lightly coloured stuff) Nothing annoys me more than beam speckles from Dust in the Aperture. Whack it on the end and you're good to go.

The only other thing needed for cleaning is a Microfiber cloth manufactured for cleaning eyeglasses or glass lenses. Avoid the use of tissues and similar materials as they are made from wood pulp and may scratch coatings and polished surfaces.