Last year, I picked up some vacuum sealable bags. You can find them at Wally-world in the storage container section. They're designed to minimize storage space.
I stuffed a complete cold weather outfit in one, including bibs, parka, inner layers, multiple socks, gloves and even skivvies, zipped it shut, and attached the vacuum to the valve and that thing compacted into an airtight, vacuum sealedpackage about 2 1/2 inches thick.
They're great space savers. I headed out to camp with three separate sealed packs. They didn't take up much room and there were no worries about contaminating them with any undesireable scents.