SG are vacuumed packed unless they are tap boxes and there is no hope for them. Some Wilsons have high salt content I forget what ones but read that they rusted the tins. I never heard anything go wrong with Toque. Most the those snuffs are fine on the shelf.
Any opened tins get decanted into air tight glass jars and are stored out of direct sunlight. Sudden change in temperature may cause moisture inside that can lead to mould or rust so best to keep at a constant room temperature don’t store your snuff in a car or shed . All F&T snuff are decanted upon delivery. Those tins decay with the salt content of the snuff.
And keep your menthols away from plain snuffs to avoid cross contamination. I have a box with scotches flavored and plain I didn’t put in glass jars and the checkerberry had gotten into a plain snuff that was next to it. it wasn’t bad and dissipated after some time but menthols will taint a plain snuff and change it for a very long time.
For extreme long term storage I suggest vacuumed packing individual tins with a foodsaver vacuum system.
Snus will keep best it the freezer in freezer bags. Open snus in the fridge in bags. Moist Snuff or dipping tobacco should be put in freezer bags and stored in fridge or freezer. Self defrosting units will dehydrate moisture. best spot in the fridge is the crisper or close to it with humidity level on high.
Pipe tobacco is best kept in airtight glass jars for ageing . I read tobacco doesn’t age in vacuumed packed tins as fast
Cigars are best in a humidor with a constant level of correct humidity.
I think I covered the bulk of it. Still have questions?