Cut Out

In order to get the shape I wanted, a CAD drawing was printed on transparency paper which was then put on a projector (its my sisters, don't ask lol) allowing me to trace the desired shape on the foam. I then cut out the shape from the foam using a utility knife. In order to make sure that board will be symmetric, I cut the board in half, used double sided tape to hold the two halves together, and sanded the edges. I am fairly happy with result.

Picture of the two halves.