Super way to practice cutting width of fabric strips. And straightforward sewing/quilting you can do on your own machine. If you do this, I recommend Robert Kaufman flannel solids over what you can find at JoAnn.
"onesie shorts from an old t shirt. I didn't like the romper, so I made my old t-shirt into a baby one. Just follow this tutorial" until you get to the part that you're supposed to make the legs, cut off the bottom, and hem the ends to make it a tee.