I've been cleaning out and reorganizing the rest into a series of tubes tubs, or as I call them, bins. The really good stuff is in the house, some in the garage, and tertiary or seasonal stuff in offsite storage. Unfortunately haven't cut down enough to eliminate the offsite. Even the 30% I have done so far has been tremendously freeing.
In addition to labelling everything and putting only certain things in each container, I now have several rules for the bins. Previously I had a large number of bins and cardboard boxes, all different. Many of the bins were old and low-quality. I had some good bins, but each time I tried to find good and cheap bins, they were gone from the store when I went back for more. The name brand is the same quality, only a little more expensive, but more importantly is available enough to build up a large stock of the same kind. Lids interchange, they stack in predictable ways, etc. Some of these bins are clear and some black. Clear is nice to see in, but I also like black because you might not want things able to be seen by anyone walking through your garage, etc. I also found that the old clear ones had more problems than the opaque ones, but that was not a detailed study. The ones that did last were the Action Packers, they are very tough but are not very efficient on space. However, the part I have organized as a "grab and go" stack is in the Action Packers. I have some colored medium size ones, red for medical stuff, blue for water containers and treatment, green for radios and gear.
Other rules:
1. All bins must have locking handles.
2. Never overload by weight or bulk in one bin - if too heavy, use a smaller bin; if too full, use a larger bin. Buy enough bins that you don't feel cramped using more.
3. All lids stay with their bin at all times.
4. Be ruthless on organization and labelling.
5. Be ruthless on throwing crap out!
Edit: Bins in the garage are on wire or metal shelves. Shelves are slowly being upgraded and standardized too.
Bins offsite are stacked up, with good bins you can stack many high and not work about tipping. Things go on the bottom based on weight and/or access needed.
Edit2: If you read some organizational blogs, you will see a common frustration or procrastination stage is putting too much time into the organization. You have to do enough to be productive, but can't let it derail you.