I don't want to buy quilt stencils (well, I do but have to be sensible).
I have arthritis and it hurts to use an X-Acto or craft knife, and I am certainly not keen on melting stencil plastic. What I do re-purposes unwanted laminated sheets of paper (especially A3 size) from work. A lot recycling centres won't or can't recycle laminated paper.
Laminated sheets already have paper sealed in the pouches so therefore stiff-ish, holds it shape and is wipeable.
Draw or print out your design on paper. If you have an existing quilt stencil that is the wrong size, use a photocopier to print out the required size
Glue the paper (design side up) on the laminate.
To cut the holes/slits, use a leatherworker's screw punch. By using the fine/smallest tip and punching one hole at a time, you can ensure accuracy in following the design and you are less likely to cut away too much or your finger!
Screw Punch
The screw punch makes a nice clean cut. Use an old cutting mat! These cutting tips can take a bite out of your mat and certainly would damage a table if you are not careful.
I can draw my registration marks, make notes and the quilting path on the paper that is glued to the laminate.
I have used this method also to make templates for applique shapes that have the 1/4" stitching line pre-printed. Just punch small holes along the stitching line, before cutting the shape outline. Now you can easily mark both the cutting line AND the stitching line!
To transfer - place stencil on quilt top/fabric then use an appropriate marking pen/pencil (i.e. washable) to place a dot in each hole or use a pounce pad. Then connect the dots with the appropriate pen/pencil. I find the smallest bit will create a hole just large enough for a crayola fine tip ultra washable pens.
If you have a clear plastic report cover, you can spray baste your design, punch the holes and then remove the paper so you can have some 'fussy' stencil placement. As the cover is plastic, you should be able to clean off the spray baste. Test the plastic first to make sure that your cleaner doesn't 'melt' the plastic.
Oh, and I have used the screw punch to put holes in fabric covered gift tags.