I am making out my Christmas list for my family and would like to get a circle cutter that will cut several sizes. I need one that is VERY simple. LOL!

I have the Fiskars Circle Cutter (the orange and clear one) but have not been able to get it to cut the exact size. I am not even sure I am using the thing correctly....

Any ideas on what circle cutter would be the easiest to use...

Thanks,
Trish