Ahhh my favorite storage section, category number two seasonal stuff. This category is actually bigger than you might think, but can also vary greatly based on where you live and how you decorate. Seasonal stuff can include everything from holiday decorations, to clothing. If you happen to have the room and the money it can also include bedding, dishes, and all sorts of things. I know people who essentially re-decorate their entire house for each season. I don't but that is because I don't have the storage to do it. If I did, trust me I would.
Seasonal storage is different that everyday storage, most people put it outside, either in the garage or a storage shed, or even in a attic or basement. Because of this there are different things that are important.
The first thing is still that you can't keep more than you have room for. I think that this is the universal rule of organizing. If you don't have the room for it you simply cannot keep it.
The second thing to think of is appropriate storage for your location. Most seasonal storage needs to me water and air tight. You shouldn't store your winter clothes in paper bags, or plastic grocery sacks. The bugs, and water, and dirt will get into them and ruin them, and then what was the point in taking up the room storing them? So look at your storage area, what is size appropriate and location appropriate. For a particularly damp location you might even need to double wrap things, putting them into a plastic cover like a Space Bag and then put those into a Plastic Bin. If you are in a drier location then you should be fine with just the plastic bin. And honestly if you are like me the Space Bag won't work for you, they always end up expanding again on me and not staying vacuumed tight, so I look at them as a big Ziploc instead of as a space saver.
The third step, one that most people forget is to label your boxes well. If you can't find what you have stored and end up giving up looking for it and buy new stuff then you shouldn't have bothered storing it in the first place. If you are using the box for things that are permanent in that box like Christmas decorations you can write on the box with a permanent marker, but if you will be changing what is in the box then make sure that you can change the label. I also put a packing list right inside the top of the box, or you can put it in a plastic page protector on the outside. So you can find specific things.
Organizing your seasonal stuff is a lot of work, but when you are done you will thank yourself. Being able to walk to your storage anytime and pull out exactly what you need without going through piles of stuff and dozens of boxes will make things so much easier, and less expensive in the long run.