I keep 90% of my parts, tools, and accessories in a Husky upright tool chest that I can roll in and out of the closet in my home office. Each drawer either has divider trays for tools and large parts or plastic organizer bins for small parts.
As for magazine storage, I use the CED magazine cases in the link below for pistol mags. Rifle mags are stored in my safe on shelves. I also have attached a Habor Freight bar magnet to the underside of a shelf in my safe that works well for holding pistol mags that can be accessed quickly.