Basically cut out the image from the background, desaturate it, fiddle with the brightness/contrast settings, run the cutout filter, fiddle with the brightness/contrast some more, then connect all the empty space (white areas) so that the entire stencil remains in one piece once the black areas are cut out.
I'm looking for somewhere local that sells beeswax sheets for candle making. The craft store chains seem to only have blocks of wax. I try to avoid buying online when shipping for the product costs more than the product itself!
I just discovered my local library has a Tool Lending Library - a branch dedicated to tools and tools alone, stocked with saws, routers, sanders, ladders, drills, and anything else you might need for a handy project. In the Bay Area, the Berkeley, SF, Oakland, and San Leandro libraries all have tool-lending branches. There may be others as well. Beats the hell outta renting from Home Depot.