Cale lost his beloved "cheep cheep" (a yellow bird he made at the art museum's craft activity) last month, so I needed two circles of yellow construction paper right away to make a replacement! I found cheep cheep between the couch cushions before we actually had to make another, but I was on the circle-cutting goal right away. And of course once I found cheep-cheep, Cale was over it. Kids!
For my first round of circle-cutting, I started with my old Fiskars Ultra ShapeXpress that hasn't seen much action. I didn't have a circle stencil, so I had to improvise right away. I cut the large 4-inch (body) circle by moving the Ultra ShapeXpress around a toothpick. The circle was very nicely circular, but pretty large for my needs.
However, for the 1.5-inch bird head, I either needed a stencil that I didn't have, or another idea. (Using a positive template instead of a negative stencil would be A Bad Idea at that size, since I wouldn't be able to hold on to the template and move the shape cutter too -- its buffer zone is too big for that!) So for my next act, I used a medicine cup for my template and cut around it with a craft scalpel with a retractable blade (I need at least token safety to use it around my small kids who want to watch everything we do!).
I found the directness of the Xacto-style scalpel to be much more natural than the ShapeXpress. If you're really worried about your fingers, or your children's fingers, you might prefer the ShapeXpress. But I think mine is going back to gather dust.