For the last several years I've been doing it the same as Marc, lay down a ribbon of sinew down the center of the limb so that it creates a crown and focuses all of the tension on the sinew rather than the wood. Usually this ribbon of sinew is only 1/2 inch wide or so. If I'm worried that a splinter might raise as the wood bends, I'll put a layer of the thinnest rawhide I can get over the whole bow's back once the sinew's cured for a few months. I've found this approach offers me the best trade-off between the benefits of sinew (higher elasticity, holds down splinters) and the drawbacks (tedious work involved in shredding and applying it as a backing, higher weight-to-strength ratio).
