One of the biggest mistakes that people make when they decide to “get organized” is to buy the containers first. A lot of disorganized people are “stuff” people, so it makes sense that when the organization bug hits, the first impulse is to add more stuff to the situation, stuff like tote bins, photo boxes, colorful file folders and fabric covered boxes of all shapes and sizes. So often this tendency just creates more clutter, wasted time and money and general overwhelm.

There’s no way around it: you have to do the work part of the organizing before the shopping part of the organizing. First, you need to determine the volume of the stuff you want or need to store. If it’s paper, there will be a tremendous difference in volume once you’ve examined and sorted all the paper around the house. So much of it will probably be recycled or shredded and won’t need to be stored at all. If you buy folders and file cabinets before you organize, you’ll buy too much.

On the other hand, some people go through the home or office and unearth reams of papers from various closets, cabinets and drawers and find they need twice the storage they thought they would. If they purchased storage before the gathering part of the process, they would have to make a second trip to the store or do a second online search and unfortunately, especially lately, the style of items they bought the first time might be out of stock or discontinued. If you’re like me and want all your storage to match, that is incredibly frustrating.

Similarly, whether you’re hanging clothes, storing toys or putting away spices in the kitchen, you need to know what the final volume of the category is before you buy the storage. I have clients that greatly overestimate their needs and others that greatly underestimate them. It causes a lot of back and forth to Ace Hardware stores, Target and Home Depot, currently Napa’s most dependable carriers of organizing supplies.

Volume isn’t the only question you have to answer before purchasing storage. The size and shapes of objects will determine what size and style of storage you get. For example, if you’re storing magazines, you’ll need to know what the largest size you’re keeping is before you buy the magazine caddy.  So, measuring becomes essential and a tape measure is one of my most valuable tools. When buying containers for drawers, you’ll need to measure the drawer, and don’t forget height—so often the container fits the width and length of the drawer—but then you try to close it and it’s a no go.

When buying containers for the garage or deep storage, especially high shelves, don’t go for heavy materials like wood or the thicker plastic. Go as lightweight as possible. Also, there’s something about clear containers that looks more spacious, clean and makes the contents easier to identify. Even labeled, opaque containers are mysterious and oppressive somehow, at least to me anyway!

Finally, I hope you won’t waste your time buying containers online, even though there may be better selection or it is inconvenient or impossible to make a trip to the Container Store or wherever right now. Too often containers come munched, no matter how careful the shippers may be. Plastic used for containers is brittle and I can almost guarantee at least one will arrive cracked or with a corner completely busted out. Cardboard photo boxes get crunched and bent easily. This is incredibly frustrating in that you have to worry about shipping back the damaged product, tracking your refunds, waiting for pick-ups and the like. Of course, it is also a terrible waste of goods and between the materials and the shipping, contributes to pollution of our environment.

So bottom line, gather, sort and purge first, measure twice, buy once and buy in person whenever possible.