I have trouble getting plasticard in my area so I order from Hobbylinc.com
http://www.hobbylinc.com/Model_Scratch_Building_Plastic_Supplies
I have found a few things that work.
First I have given up on trying to cut all the way through... instead I score partially and snap it.
Cut along a steel ruler, then bend the card along the line of the cut and it will snap easily.
for working with templates..
I place the paper template on the platicard and the use the point of a hobby knife to mark the corners of the pattern. I then remove the template use a metal ruler and hobby knife to score the lines between the marks. (connect the dots). Finally I carefully flex and bend until it pops out.
For perfect circles I use a tip I found on dakka... I forget who..
This 9 piece die set made for punching sheet metal works perfect(harbor freight)
For bigger circles I have had some success with one of these circle cutters i picked up at a craft store for 4 dollars.
for very small circles and big rivets I use a leather punch...
Anybody have any other tips? I would especially like to hear ideas on how your transfer your design from a paper template to the plasticard.