This is going to
seem complicated and obsessive - actually takes less time to do than it took to write this little "guide".
Cleaning with warm soapy water works nicely to remove the usual "stuff" that collects on mechs. Dry with compressed air (compressor or computer blast cans) or just soft cotton toweling. Some prefer to use nothing but 99% IPA... which I have no issues with if that's your preference.
If the nickel contacts have a bit of corrosion, that can be
gently removed with a fine scotchbrite pad, equally fine stainless steel wool or sponge - or 600 grit or finer wet/dry sandpaper. Rinse cleaning residue with 99% IPA.
Make sure there is no water remaining inside prior to installing a battery.
Although I prefer
MG Silver grease on contacts and even threads (link for tech reference -
buy from Amazon - it's cheaper) - it can be a bit expensive for some - so what ever your
preferred anti-corrosion electrical grease - Noalox, Ox-Gard, NO OX ID A and so on. Bare, clean aluminum works just peachy too.
If it's bare, polished aluminum
with no anodizing, you may polish it with any common aluminum polish - Mother's, Simichrome, Nevr-Dull - what ever you like - to a mirror finish.
Finish with a light coat of (specifically)
Renaissance Micro-Crystalline Wax to all exterior surfaces (read up on this and you'll understand why it's preferred) - work it in with your fingers.
Buff lightly to remove residue ("extra soft" toothbrush for grooves/crevices) - it's not type III "hard" anodizing, but rather the, still quite durable but more cosmetic in nature, type II - so don't get too aggressive with hard rubbing.