Hey everyone! This is my first post. I tried to make something fairly simple that is somewhat affordable and can be made without sophisticated tools. Here goes.
Total cost: about $100 with some leftover materials for my next project.
Tools: circular saw, hand plane, drill, bar clamps, paint brushes, level
Materials: four 1x4x8, two 2x4x8, two 1x3x6, bottle of glue, 60 grit sand paper, 150 grit sandpaper, 320 grit sandpaper, screws, 16oz of prestain, 8oz of stain, 16oz of polyurethane, rags for staining
First step, buy the wood. I went to Lowe's and bought surfaced pine (S4S meaning surface on four sides). Unfortunately, they only sell red oak, poplar, and pine where I live; pine is definitely the cheapest. It cost me about $65 in wood and I bought the highest quality (and a little over priced) pine they had. I bought eight boards: four pine 1"x4"x8' long, two 2"x4"x8', and two 1"x3"x6'. I had all of these boards cut in half. They have a saw and they will either do it for free or charge you something like $1.
Step two, glue seven of the 1x4x4s together. Try to make one end perfectly even (with a speed square or a straight board) so you only have to trim one end. It is much, much easier if you glue one board at a time. Give the glue at least 30 minutes to dry while clamped and then add the next board. Once they're all clamped together, leave overnight if possible to dry. The more even the boards are the easier the next step will be. Contort the boards so they are level with each other if at all possible.
After they're all glued together, trim the ends so they're even. Plane them so they're even. I don't have access to a nice machine plane so I used a hand plane and sandpaper. Round the edges so they're not sharp and don't rub on your elbows and legs. I used the hand plane and sandpaper (~60 grit) to do this. Make sure all the excess glue is removed and the boards are even with each other to your desired perfection.
Tip: sand the end grain finer than the rest of the wood or it will absorb more stain and be darker than the rest.
Next, build the box frame. Clamp two 2"x4"s together so one end is even. Trim the other end to 45 inches of both boards at the same time. In the same manner, trim the remaining 2"x4" pieces to 19.5 inches. Clamp the four pieces together in a box shape and screw or glue it together (I screwed mine together, all preference). I also added an additional 19.5 inch piece to the middle for strength. You can see it in the picture. If you do this, make sure you flip it the opposite way of the others and that it is perfectly flat with the top surface so you can screw the top to it.
Clamp the 1x3s together and trim them in the same manner as the previous step to your desired height for your legs. Mine are 29"s and that is just a little higher than most desks. Attached them to the box frame. This is a tough step. I'd recommend attaching the first one where you think it looks right and then clamp one adjacent it and make it match. Then attach the other legs in the same manner. MAKE SURE THE FLOOR IS LEVEL. If the legs don't balance perfectly on a flat surface, measure from the base of the frame and see which is the longest (you can try and see which leg is holding the most weight if you're able). Sand as needed until they are level.
After this, glue the top to the frame and legs and clamp it. I screwed the middle 2"x4" to the top before I removed the clamps.
In the picture you can see a board between the two legs in the back. I didn't plane on attaching this but did to make it a little stronger. It was a little wobbly from side-to-side so I used the extra 1x4x4 to sturdy the back. I measured the distance from leg to leg and then cut it about a 1/4" short and glued and clamped it where it needed to be. Make sure the floor is level for this step if you're using a level.
After this, sand and finish as needed. I would use pre-stain if you used pine. I prestained once then stained twice with Minwax colonial maple and then put multiple coats of polyurethane on. Make sure you sand between coats of polyurethane (I used Minwax semi-gloss). If you use oil based stain, use oil based polyurethane. I used 320 grit. After the first application you will have to sand a lot. If you use pine, you'll want to do multiple coats of polyurethane so writing doesn't dent the wood. After this you're done. Sit at the desk and enjoy.
If you're feeling ambitious, you can also put a small hidden shelf underneath and it will be hidden by the 2x4 border. Good luck.