My way is kinda redneck but it works like a charm for me. I can't grind my own lams yet so I buy something cheap and light in a .030" parallel, I use walnut every time. The following is what I use mainly for my 18" risered mild r/d longbow depending on draw length.
I cut a 24" piece of .030" walnut out so my p-lam will run 3" past the fades on each end of the riser. Then I'll measure like 3" or 4" from each end of the walnut and mark it. Then I use a $20 orbital hand sander for Wally world to CAREFULLY and evenly sand down the ends so they are tapered down paper thin. I do the same for tip wedges.