kegan, the ratio would have to stay the same (i'm guessing) along the entire length of the limb.  So, if it were 1" wide at the fades, it would be 5/8 deep there...moving toward the tip, the limb would become narrower and thinner proportionately.  I've never made one, but I will for this project, and i think that's how we're supposed to do it.
My blank is made of white oak:  72" long, a 5/8" belly piece with natural reflex and a 3/16" backing lam of the same wood.  I bought the board about a month ago and used this method:
It is 2" thick, plain sawn lumber.  I ran it over the jointer to get a clean face and clean edge, and then tablesawed various widths off the edge.  These pieces are all edge-grained.  
Last night I glued the pieces together and when the glue was dry I cleaned them up and cut the stave down to rough dimensions.  Let the games begin!