Well I tried to do a frame on wire wheel and POR treatment, but I only got the outside of the frame done while I was still in school. I gave up on that dream and switched to Fluid Film. I hate the mess it makes but it really does keep stuff together with constraints that most consumers have. Beyond that I always keep an oil can topped up with 1/2 engine oil and 1/2 ATF and lube joints, and anything that looks like it can hold junk or moisture - pinch welds, drain ports, cab corners, folds that kind of stuff. Sandwich metal like the gooseneck hitch and airbag mounts.

I'm a fan of woolwax or fluid film.

I think I have woolwax on my list from a previous recommendation.