Measure the area of your skin that is to be tattooed using your measuring tape and allot yourself enough paper to draw the design.
Draw a relatively straight line with a pencil on blank white paper the measured length of the desired tattoo. The line should not be perfectly straight, so it will seem to hang down in some areas when tattooed, mimicking the appearance of a real rosary.
Begin at the left side of the line and draw a large bead followed by 10 small beads, followed by another large bead followed by 10 more small beads, followed by a large bead and finally 10 more small beads. After this group of beads, draw a pendant in any form you desire -- but it should be larger than the large beads. After the pendant, draw 10 small beads followed by a large one and 10 small beads. It will look lopsided on paper, but when you match the ends together for the stencil it will form the perfect rosary loop.
Draw a cross or faith symbol of your choosing on another sheet of paper with a small line leading up from it. On this line, draw a large bead closest to the faith symbol followed by three small beads and another large bead. This line will be connected to the pendant of your rosary loop when applying the stencil to your skin.
Outline your pencil drawings with a black marker once they are completed to your desired specifications, and erase away the pencil lines once you've finished.
Tape a piece of tracing paper over each marker drawing and tape the corners together in order to keep the pages from sliding apart.
Place the two taped pages over a lighting table or well-lit drawing desk, stencil paper up, to ensure the lines show through.
Trace the image onto the stencil paper with a tattoo stencil pencil and remove the tape once you are finished.