First of all, you need an enclosed cargo trailer to proceed to any construction work. The size of the trailer will determine the shape and volume of the deer blind you shall be constructing upon it. You better thoroughly wash out the trailer using a pressure washer and clean out the exterior and interior of the trailer. Then, park the trailer on a sloping surface, making sure to chalk the tires, and leave it there overnight to completely dry up.
Once the trailer is dry, park it on a levelled ground and chalk its tires safely. Use a green spray paint and apply a coat of paint all over the exterior surface of the trailer. Let the paint dry afterwards.
Attach small leaves and branches on the trailer using pieces of duct tape and then paint the trailer tan. When the second coat dries up completely, remove the leaves and branches from the trailer.
Use 2-by-4 lumber and ½ inch plywood to build a bench on each side of the trailer. The benches need to be 4 feet long and 2 feet high. You can use table saw to cut the pieces of lumber and then use 3-inch wood screws to connect them together to form the benches.
You will need a sawzall for cutting out a shooting and viewing window in each side of the trailer. Make the window one foot tall and four feet long, and also attach a shelf bracket to the bottom of the it with metal screws so that you can rest your gun for shooting.