I store bulk blends or opened tins in mason jars, and I've never had an issue. I currently have about 50 plus jars in my pipe cabinet. I have some tobacco's that have been stored this way for 8, 9, and 10 years and they're still in great condition for smoking right out of the jar.
As for my tins, I just leave them as they are. About once a year I'll go through my pipe cabinet and sort through my tins to see what I forgot I had, and I'll give them a quick once over, but that's it. I don't do anything special. I've only ever had one tin go bad on me, and that was a Seattle Pipe Club tin. That one had holes develop in the bottom; however, there was no rust on the inside, so I have no idea how the holes got there. Only the tobacco right over the few holes was dry, the rest of the tin was fine, and it smoked fine.