Find a good quality gun oil that you like the smell of. That's about all there is to it for preserving stainless steel that's not being exposed to harsh conditions. I happen to prefer the cinnamon scent of Weaponshield CLP. There's a product called INOX that I also like the smell of, some folks say it has no odor but I pick up a definate sharp almond like scent. What you shouldn't use is Militec-1, great lubricant, not a rust preventative. This is first hand experience, I know Militec says it's a great rust preventer, I happen to disagree. It can accelerate corrosion under humid conditions. It's been 10 years since I've bought any and maybe the stuff they're selling now is better, but I wouldn't bet on it.