I lack work space in my garage, and every horizontal surface becomes a place to stash things. This leaves my table saw and router table covered with tools and parts, and even used as an additional work bench.
In order to make my place begin to resemble a real shop, I made a workbench along the wall.
I purchased a sheet of 23/32 plywood from the blue box store. I had them cut it in half so it would fit
easier into my minivan. On the way home a ball rolled into the street and I hit the brakes. The plywood pieces that were standing on end between the two front seats slid forward and cracked the conform console on the dashboard. Oh well, at least no children ran into the street and were hurt. Not cracking the console were three 8 foot two by fours. I needed 4, but I had one at home I could re-purpose. I also bought six 3 1/2 lag screws and washers.
I found the stud on one end, and drilled and fastened it at my desired height. I used a level and went to find where the screw at the other end would go. Either due to the studs being not quite even or a miscalculation on my part, the board didn't reach the last stud I thought it would. I moved in to the next stud. It was OK, I goofed and only bought 6 lag screws anyway.
I took the board down and cut 5 cross pieces. After I started screwing them to the long 2 by 4, I realized that I didn't give myself enough overhang for clamping. I shortened them by 1.5 inches and attached them again. Then I screwed on the front 2 x 4.
I fastened the whole assembly to the wall. I had forgotten to make holes for the other lag screws earlier so I drilled through the 2 by 4 into the wall at each stud, took the assembly down and drilled into the studs, and replaced the assembly and tightened all the lag screws.
I cut the 3 legs. Using a level, I clamped each leg so I would be on he floor and be holding the top level front to back. I attached a leg with screws in the middle and at both ends. I then decided that I made it too high, so I lowered it to about 36 inches at the bench top and did it all again.
I screwed down both half sheets of plywood on top of each other for the work surface. I didn't glue because I'm sure I will be replacing these in the future.
I put a 1/4 thick lip to fill in where the top doesn't go all the way to the wall to prevent small items from falling in the gap.
It is so uncluttered. That won't last.
You can find plans in Sketch Up.