Also, if you get really turned around, make sure you can see the rings clearly on one of the ends of the stave (you might have to rasp or sandpaper it, then reseal with clear glue or shellac, etc.), then start chasing from the very end so you can see, in cross section, where you are jumping rings. Hopefully that makes sense. Once you get that first inch or so on the end, make sure you go slow and are working in good light so you can see the contrast between rings.