Just follow these instructions, or the videos at the bottom
You must be using the Google Chrome web browser on a desktop computer to use Audience Intersect.
Go to www.audienceintersect.com/login and sign up for a new account. You must use your Teespring email address to sign up.
Click "ADD INTERSECTION" to add another intersection.
Note that each row counts as an "AND" (an intersection), but each interest within the same row counts as an "OR", meaning that it will include users who match any of those interests.
You can change the category using the dropdown menu. Enter in new intersections and watch the audience size narrow down.
Installation and Tips