Helen,
Here’s my 2 cent’s worth of advice (and 30 years of teaching sawing to my students): use rubber cement.
Same application as Jo mentioned with contact cement 1) clean metal surface 2) apply a thin film of cement on both the metal and the paper. 3) let the glue get tacky (about 15-20 seconds). 4) carefully position the paper on the metal. 5) rub all the air pockets out from between the paper and the metal. 6) saw out your design. 7) peel the remaining paper from the metal.
The biggest advantage of this method, IMHO, is the clean-up after sawing. All you have to do to get rid of the remaining glue is rub it with your thumb/fingers. No acetone.
If you are doing two identical pieces - say for earrings - I use the method described in Alan Revere’s instructional videos. Glue a piece of paper between the two sheets of metal. In this case I will use an adhesive that has a stronger bond like the contact cement metioned.
Good luck,
Mike