Start by drawing your design on some regular old paper.
My design kept getting bigger, so I taped two sheets together. You are going to transfer the design to freezer paper anyway, so don't worry about erasing your mistakes. (If you aren't confident in your drawing abilities, you can print something out and trace it. But make sure you aren't ripping off someone else's work without permission. Be cool.)
Next, place your design underneath a sheet of freezer paper and trace it neatly with a sharpie.
The marker gives your lines greater width making it easier to cut them out and paint them in later.
Now place a piece of cardboard under your freezer paper to protect your table while you cut. Start by cutting out any "inner" shapes.
Important: Set these shapes aside. DO NOT throw them away!
You have to iron them onto your shirt later in order to complete your stencil.
After reserving your inner shapes, cut out the rest of your design and trim down the excess paper around the outside. (You can throw these parts away.)
Iron the main body of your stencil onto your shirt.
Then add those little inner shapes to the correct places and iron them down.
Place a piece of cardboard between the layers of your shirt to prevent the fabric paint from bleeding through. Use a stiff brush to apply your fabric paint.
It may take a couple of coats to get good coverage.
Peel off your stencil while it's still wet, then allow your paint to dry according to package directions. (And some fabric paints need to be heat-set, so read the label!)
Once it's dry, you can wear your custom tee around town.
Perhaps to a showing of Harry Potter?
**Update: Interested in buying one? Check my
etsy shop. Convo me if there aren't any in stock!**