Begin by setting a letter to use as a rough guide:
Then consider how you wish to create the design and which features you’d like to simulate. In this case we’ll want 4 boards, and 5 nails. Since this is subtractive, and Carbide Create will create the layering / 2.5D / 3D effects when we make toolpaths, it’s simple enough to start from the top down and work our way from the inside out.
Begin by drawing a circle the size of a nail head and positioning it as desired, then duplicate it as needed and drag the duplicates to where one would want them to be:
(it may help to turn off Snap to grid)