Begin by clearing a workspace for yourself that is sufficient enough to accommodate a large piece of drafting paper along with your other materials such as pencils and rulers. You don't need to have a drafting easel or any special equipment, a large surface like your kitchen table will work just fine.
Lay out your paper and materials in an organized and accessible manner. Make sure that everything you need is at the table so you don't have to get up in the middle of the drafting process. Getting up to fetch extra things could disrupt your concentration and slow down your project, so try and stay put once you get to work.
Design the base of the shed. For a sturdy and reliable garden shed, your base should ideally be made from concrete and be a rectangular shape. This step is very important because it will determine the size and measurements for the rest of your shed.
Create diagrams for each wall and label the appropriate measurements. Your garden shed should have four walls like any standard shed plan, but you need to make sure that you include measurements that detail the various lengths of wood to be cut. Each framed wall should have the studs spaced at least 16 inches apart and have a complete header and footer.
Illustrate the diagram for your roof. You can use ready made trusses and adapt your roof design to those, or create a separate design for your own trusses. Either way, you need to carefully reference your base and wall diagrams when drafting your roof to make sure that all of the measurements agree.
Make notes of your preferences for shingles, paint, and any other exterior feature. This can be done by drawing arrows to the specific parts on the diagrams and labeling your preferences, or by creating a separate table somewhere on the first page of the plans.
Draw a table for your bill of materials that contains everything you'll need to complete the construction of your garden shed. Reference all of your measurements and previous diagrams to get an accurate estimate of the correct amount of materials required for your project.