The key steps in building a custom shed are: 1) Construct a solid foundation 2) Build a sturdy floor frame and cover with sheeting 3) Frame the walls to the desired size 4) Construct the roof frame 5) Add exterior siding 6) Install plywood roof sheeting 7) Shingle the roof 8) Add windows and doors 9) Install ventilation 10) Add decorative or functional elements like shutters, roof drainage, and a ramp. Building your own shed requires a set of special talents and special tools that not everyone can possess. If you are a handyman and have the tools you need, doing it yourself will help you save a lot of money. However, if you lack the skills and knowledge to build the shed properly, it will be better to hire a professional.