I have used a dremel tool (high speed rotary tool) with an abrasive cutting disc. Some care needs to be used as an abrasive disc can burn the board if left in one place too long. Also you need a steady hand.

I have also used a scroll saw. This also works well.

Do not use a roto zip type tool! This proved to course and hard to control.

I have never tried a paper cutter. I will give it a try next time I have the chance.

Regards,

Joe Kupcha