While having a craft cutting machine like the Silhouette makes making these types of t-shirts easier, it can certainly be done by hand. Before I got the Silhouette, I used small, sharp quilting detail scissors/an exacto knife to cut out my freezer paper stencils and applique pieces.
Here are the two shirts I made my kids this week that I’ll be using as an example to demonstrate the process. Today, the Cherry tee and tomorrow the C-17 Air Force tee.
Before I cut the fabric, I ironed on some Heat N Bond Sewable Adhesive to the wrong side of the pink polka dot fabric. Then I picked a design and had the Silhouette cut the fabric. To do this by hand, google an image, print it, and trace it onto the Heat N Bond. I often trace the printed image with a black Sharpie so it’s easier to see through the Heat N Bond to trace it. Iron your Heat N Bond to the wrong side of your fabric and cut out the image.
If you used the Silhouette, the fabric pieces should peel off your cutting mat with the adhesive attached but not the backing. If you do this by hand, peel off your backing. Set the pieces aside for the moment while we do the freezer paper portion.