Use Tulip Stencil Spray Adhesive to get picture-perfect results with stencils! This reposition-able adhesive provides even spray coverage on stencils for a secure, temporary hold to fabrics in order to prevent shifting and seepage when applying paint.
DIY Moroccan-Style Wall Stencil Tutorial - tape a level to your stencil to get a perfectly straight pattern. So smart, cheap and easy, I wonder if there's a way to do this with paint that will wash off? Maybe chalk and water and hairspray?