This is the tool I use to remove tiny cuts from my Expression mat. The blade tip is a rounded point and it's thin enough to slide under light weight paper making it super easy to get those smaller cuts off the mat without tearing or messing up the edges.
Painter's palette knife
The angle on the metal portion helps to slide it under your paper
I found mine at Hobby Lobby for $3.99 and used a 40% off coupon, of course! Cheaper than a Cricut spatula and a lot thinner. I have the spatula but don't care for it since it's so thick. It tends to clobber up the edges of the paper before I can get it underneath to remove it from the mat.