Here are a few more details. I took 4 pressure treated 4"x4" x 10' that I had from a previous purpose. I found a pile of 2" x 6.5" x 13" boards that were weathered and haphazardly stacked. I snapped chalk lines and straightened them up for use. I used these for the everything you see in the first pic. Since I could easily get 6' x 12' that is the size I decided to build. My ground is very rocky. I strategically dug holes as deep as I could and positioned the 4x4's. Before backfilling I got them plumb and nailed one 12' floor support. Then nailed a 6' then the next 12' and then the last 6'. I had a sliding door given to me that I used as the window. I put one of the 12' roof supports level and nailed it. Shed roof was easiest so I deducted 3" for every foot (actually I deducted 20"'s on the back to give me adequate pitch. Before nailing the back 12' roof support I marked all the 4x4's and cut them the correct roof angle. I wanted plenty of ventilation so I purchased new 2x8x8" for roof rafters. I could have engineered something as good without spending that money. At first I went to several manufactures and picked up some skids. They were all build different and pretty rough. I cut the nails off with a sawzall so the lumber would not get damaged. Later I found a major distributer that had many pallets that were identical in size and all built the same. I took a circular saw and cut off the end of both sides of the skids leaving the nails with the supports and only had to use the sawsall to cut the center support. I used these center supports to make my doors. I strategically placed nailers so as to maximize the length of the boards. I used a board and batten approach to block out all the gaps alternating one board up to the roof next board down to the floor. Any questions feel free to ask.