I’m not one to reinvent the wheel – Blackfly Canoes already have a great writeup on how to carve a saddle. Click on their logo below to go check it out. My only alternative recommendation is to invest in a 9″ fillet knife (I’m a fan of the Dexter-Russell 2333-9PCP) and a honing steel for carving foam. Steel the knife repeatedly while working to keep the blade sharp so that you can make accurate and thin slices with ease.