an alternative to this is just as easy and quick and requires no tracing or snipping with a pair of scissors. this method works best for pans like spring form ones with a shallow edge. it also uses a knife. if your concerned about damaging your pan through the cutting process, then you may as well opt for the traditional way of doing it. i've not had any problems using this method and not incurred any damage to mine.
fitting parchment to spring form pans
remove the spring form part of the pan and place the bottom on your counter.
cut a piece of parchement a little bigger than the bottom of your pan. place the parchment over the bottom of the pan.
with one hand hold down the parchment in place and with your fingers of the other hand, crease all around the inner edge of the pan well with your finger nail. if the paper slips, just fit it back into place following the edges of the crease you've made.
once the entire circumference has been creased, take a very sharp knife to cut. holding the paper down with one hand in the center, cut directly into the crease at the edge of the pan, turning as necessary.
make sure to cut well as you go. if it is still attached in small spots, then cut it out with the knife following the crease.
place in the bottom of your pan and use as required.
the parchment will stay flat if you dab a bit of butter or margarine underneath it or directly on the bottom of the pan.