Are we understanding 'bushcraft style' to mean a scandi fixed blade with a full tang? If so, I like to use a deep leather pouch sheath, form-fitted to the knife. It looks nice, ages well, and works for me. The only drawback is that this style of sheath is not waterproof.
Now, if we extend the question to cover sheaths for knives that are used for bushcraft-type tasks, I have come to appreciate the merits of a synthetic sheath. For the last few years, I have used a Spec-Ops nylon sheath with a form-fitted insert. This sheath is perfect for my year-round outdoors needs - it is waterproof, has good retention (both from the fitted insert and the retentions strap), has a 'drop' design that lets it hang below my pack when hiking, has a space to attach a leg strap (hand for paddling or climbing trips), and can be partially disassembled and allowed to soak in warm water if it gets gunky. I find it particularly useful for off-trail snowshoe excursions, where my sheath is likely to get covered in bits of wood, snow, and pine sap.
All the best,
- Mike