Once a person starts prepping in a serious way, the first thing they run out of is usually shelving. Cheap steel shelves can be had from auctions, but that's catch-as-catch-can. When you need shelves right away, it often becomes a choice of build or buy. I'd rather build, and (fortunately) there are a number of cheap shelving schemes out there in Internet Land, but I'll start this off with the cheap system I designed and presently use. The 1X2 Shelf System is used against stud walls, and incorporates the strength of the wall into the shelving. The only materials used are 1/2" plywood, 1X2 furring strips, and nails or drywall screws. Sort thru the wretched pukewood they sell for 1X2s these days, and pick out only straight solid ones. Building with crooked wood just builds crooked things. A miter saw makes the cutting easy, but a table saw or even a jigsaw can get the job done. Other than that, all you need is a hammer or screw gun, a tape measure and a pencil, a level, and a small try-square. Decide first on the length and width of your shelves. I usually go with 9.5" W X 8' L shelves, because five will cut out of a sheet of plywood with zero waste. Have the shelves cut on the panel saw at the Big Box DIY Store when you buy the plywood. (1/2" plywood is a lot cheaper than 1" boards, BTW) Decide on your shelf spacing. I usually go with 12.25", which nicely accommodates a standard Christmas can/popcorn can. 12.25" spacing in a room with 8' ceilings will give you 7 shelves, with the top space being only 6.75" tall. That's not a very handy space at the top of the shelves, but if you put it in the middle of the shelving, it becomes very handy indeed. It's just right for a lot of small stuff. So your shelves would be four spaces 12.25" apart, one 6.75", and three more 12.25" apart. That gives you a nice tall 12.25" shelf at the very top. It's a useable space even if the ceiling is a little bowed or the room isn't quite square. I use four posts on a 8' long shelf, which requires four 1x2 front posts that reach to (about) the bottom of the top shelf. They should be 83.25" long. (Don't worry about the fact that 1/2" plywood is slightly less than 1/2" thick. It'll work out ok.) The four back posts are (preferably) four studs in the wall the shelves are built against. So find the studs, and mark them at the middle with a long vertical line. The next step is to cut the shelf spacers. You'll need 56 spacers. 48 will be 12.25" long and 8 will be 6.75" long. Cut them on a miter saw, if possible, so they are all exactly the same length. The shelf spacers eliminate the need to notch posts for shelves to fit into. Better to do 58 crosscuts than 58 notches. Trust me on that. Attach one long spacer flush with the bottom end of each front post. Half of the spacers will be attached to the wall. If you have base trim in the room, measure its height, and cut that amount off the first four back spacers. They're the bottom row. Attach them to four studs, set firmly against either the floor or the top of the base trim, whichever way the wall is made. You are now ready to turbo-assemble the shelving unit. Lay a shelf on the back spacers, and hook a front post under it at each end to hold it level. Attach the shelf to the front and back spacers with one vertical nail/screw, each. Position the other two front posts along the shelf and attach them. Use the square & level to keep things, well, square & level as you go. Attach four long spacers set firmly against the first shelf to the wall, and four to the front posts, and then add another shelf. After four shelves, put in the short spacers to make the short shelf, and then continue right up to the top of the posts. If the posts are a tiny bit taller (or shorter!) than the top shelf it matters not at all. By the time all the shelves are attached to the posts, sandwiched in the spacers, and attached to the spacers and the wall, you shelves will be a solid as a rock. And they will be plenty strong enough. One thing about the shelves: 9.5" may seem a little narrow for, say, a 12" diameter Christmas can. I've found that having large cans or boxes slightly overhang the shelves makes getting them down a lot easier. If you are building into a corner, the side wall become a front post. (Saves wood!) As for finishing the shelves, why bother? It just makes them more expensive, not more efficient. But do so if you wish. This has been a wordy post, but I make it a thousand words longer by adding a pic.