When you have finished your design for the space, draw at least one section line through your design similar to the line labelled A-A in the figure below. Create an accurate section drawing from it by drawing lines (up or down in this case) as shown in the second figure below. The second figure here shows that our choice for the location of the section line could have been better. Can you see that your section line should be chosen to show the most important features of your design and not inserted at a random location.
The section line
The section itself
Send the resultant drawing as an attachment to an email to info@gardencad.net