Keep Shed Framing Straight
The trick for learning how to build a storage shed is to stretch the line across a scrap of wood at each end so there's a space between the line and the part you're straightening. On a wall, for example, tack small scraps of 1/2-in. plywood at each end of the top plate and stretch a line very tightly over the plywood. Then use a third scrap as a gauge to check the distance between the line and the lumber. Use braces or whatever is needed to adjust the top plate until the gauge just fits. Now your top plate will be perfectly straight.
Choose Straight Studs
In a perfect world, all of the studs would be straight, but since they aren't, make sure to pick the best ones to use at corners and at door and window openings. Sight down the length of the studs and set aside the ones that are perfectly straight. While you're at it, also set aside studs that are really crooked. You can cut these up to use as cripples or blocking. You may find other uses for short pieces later on.
Dress Up a Plain Shed With Trim
Whether grooved or plain, installing 4 x 8-ft. sheets of siding is a fast and economical way to cover shed walls. But the result can look pretty plain. Adding wide corner boards, wide window and door casing, and maybe a horizontal band at the base and top can turn a utilitarian-looking shed into a masterpiece.