My little blue owls started out as matryoshka dolls which took a wrong turn. I corrected them and turned them into little owls. I free handed them, but you could definitely use a cut-out stencil you've created.
I use both fabric paint and acrylic paint, all depending on what colors I have on hand.
Once you've painted your design on the fabric, let it dry completely. Then place a lightweight piece of cotton over the painted area, and iron with a dry iron. That will help set the paint so you can wash the article of clothing.
(If you're interested in what I did for the gingham pants, I simply used heat and bond web on a fabric apple I cut out and ironed on to adhere.)
Give it a whirl sometime. It adds just the right touch.
Keep warm this weekend! We'll be happily welcoming back Bobby to our neck of the woods. Sigh...