I either print out a paper copy of my pattern when I get it or trace the pattern onto wax paper so my original is never used for cutting. If my copies should get too worn, I have the original to copy and start again. For most projects, I prefer wax paper to copy paper as a roll of wax paper is inexpensive, and allows me to clearly see the fabric underneath so any stripes are straight or motifs are centered. If I think that I will be making many multiples of an item, I make a clear template plastic pattern and trace my patterns onto fabric. When I have curved or irregular shapes, I always cut with a scissors or shears as it is easier for me to cut accurately than with a rotary cutter.