I keep my Hops in the freezer and use the plastic bag sealing things once opened. I have all my malts in air tight tubs in a cupboard in the kitchen. Except my pale malt which is in a big plastic bin in the consevatory.
I keep everything under the stair. It's dry and away from bright light. I know hop deteriorate faster the warmer they are but I've no space in freezer so I just use them and don't store them for months on end.
grains are in a blue bin, similar to ones people use as boilers, all in bags
main grain is sat on the table in the garage in the sack it came in
looking at something for it now, probably a large wooden cupboard
hops are in the freezer in the garage that has the overspill and fruit we have stewed for pies etc