I spray the back of my stencils with a repositionable adhesive. My favorite brands are 404 Spray and Fix and KK2000 from Sulky. We don’t sell the sprays in our online store due to the shipping restrictions on aerosol cans, but you can find them at most sewing machine dealers and some big sewing stores. (The sewing people use the sprays with machine embroidery.)
I call these sprays “Post-it Notes in a Can” because that’s exactly how they work. The spray keeps the stencils from moving on the fabric. The spray stays on the stencils and does not leave a residue on your fabric. Pretty neat.
