I keep all my small brew day stuff in 1 bin that I bring up from the basement on brew day. It's a plastic bin with a latch top with nice "grippies" on the side. I still have to lug up my mash tun, hlt, boil kettle, mill, 2 buckets, mash paddle, auto siphon, etc... hahaha. All that's actually in the bin is my starter stuff (stir plate, large beaker), refractometer, hydrometer stuff, spare hoses, fine mesh strainer, scale for weighing hops, and a few other small things.
Either way, bin or no bin, I'm still making several trips up and down the stairs. I figure I have to work off all the tasty beer calories somehow!
I have my basement brew stuff organized by a brewing beer side and a packaging beer side. That way there's some kind of order to where stuff goes. I just moved in June so I'm still figuring out where stuff goes and how it's all going to work but it's a start. I was working with a lot less room before we moved so it's an upgrade either way.