Hello Scott,
The thigh braces are built by gluing a block of wood to the coaming wall - it is best to preshape the block as much as possible and then fine tune the thing after it has been glued in place. In order for the block to "hook" the thigh it is necessary to angle it downward from the coaming wall - do this on the bandsaw by setting the table to at least 15 degrees (more if greater "hook" is desired). It can be a little tricky getting the block to fit nice and tight - you'll need to shave a little here and a little there - but eventually you'll approach something that appears to have grown out of the coaming wall. Sizing the brace depends on the size of the thigh, the "degree of grab" you desire (see Shawn Baker's braces), and the width of the cockpit opening. You can fine tune the fit to the thigh by adding minicell foam to the underside of the brace. After the foam is fit, try adding 1/8" or 1/4" neoprene as it is not as slick as wet minicell and grabs the thigh much better when rolling and bracing.

Hope this helps.

Joe G