Updated: Feb 2, 2020
Years ago I had a book, Use What You Have Decorating. I found it so helpful that I expanded the concept for organizing too.
The basic idea of "use what you have" is exactly as it sounds. Before you go out and buy new furniture or fancy organizers, use stuff you already own. The piece you have may work just fine, or you can use it to test your design idea. For instance, I have a cushioned bench that has not only been a bench, but also a stand in for a small sofa, a coffee table, and a console table. Before I bought anything new, and often after I measured the space for what I thought would work (spacial reasoning is not one of my strengths), I'd stick that bench in the space for a while to test if I used the space as I thought I would, if the scale was right, if the item interfered with walkways, etc. If I needed to test color, I'd throw a sheet or blanket over the bench in a color close to what I thought I wanted.
Sometimes, I'd save myself a purchase because I did not use a space as I anticipated, which happens a lot right after a move, by the way. Other times, I'd adjust the size of the item I ultimately bought because, say, the bench was small even when I accounted for the extra inches I planned on from my initial measurements.
The using what you have process takes longer but is cheaper and greener. I'm far less likely to replace and trash or donate a purchase that I tested before buying because it is more likely to work as I need it to work.
Use what you have organization works in a similar way. Instead of buying drawer organizers, for instance, I reuse nice boxes. I prefer sturdy ones without a lot of graphics that can coordinate visually, so I tend to save ones from certain brands. Apple product boxes are a perfect example. (Well the lids are. They glue down the forms in the bottom and the box often rips when I pull them up. It rather vexes me.) Apple boxes are sturdy, white without lots of graphics on the sides, and shallow enough to fit in desk or bathroom drawers but still deep enough to hold a variety of things.
Configure the boxes in a drawer as needed and change it around until the drawer works for you. When I first started doing this trick, which I actually first saw from my grandmother, I planned on getting a proper organizer after I had figured out the configuration I liked. I usually end up preferring the boxes over plastic organizers, though. The plastic store bought ones are needlessly expensive, not as versatile, and they get a grimy black coating after only a little use. You have to empty the whole thing and scrub with hot soapy water to get some of the black off, whereas if my boxes get icky after a while I can swap out a newer box or line them with paper — decorative or plain, as I prefer.
(Of course, you could do this upcycling, paper covering from the start, but we are talking bathroom and desk drawer organizers. Is it really worth the couple of hours it would take to cover the boxes that no one will see but you? I'm all for making it visually tidy, but that is mostly accomplished by the types of boxes saved.)
The picture for this post is my bathroom drawer. The cotton ball holder isn't a box but a glass punch cup I inherited from my grandmother, the same one who did me the box trick, actually. (I don't know anyone who makes party punches anymore, but the old punch cups are another source of use what you have drawer and vanity organizers.) For a non-drawer example, I have some UGG shoe boxes in my closet where I store the kids' stocking stuffers until Christmas.* Same deal, sturdy, plain (brown cardboard in this case) and easy to stack without looking messy. And if the box starts to get full, I know I'm overstuffing their stockings.
Other use what you have ideas: Tape together delivery boxes to test bookshelves or mudroom racks. Cut boxes up in artwork sizes to test a gallery wall. Use kitchen chairs to test the footprint of occasional chairs. Purchase a folding table for the garage but in a comparable size of a console or kitchen table to test size or shape before buying the more expensive piece of furniture.
Use what you have. I've not read the book in years, but I've practiced it to great success since the early 2000's.
* I'd worry about publishing where I stash the stocking stuffers, but my kids will not read this blog. As one of my daughters quipped to a friend who asked about my podcast, "I don't listen. I get the live show."