As the guys above have said, bevel down and 6 to 8 inches at a time.
Osage was my first time to chase a ring too and I was overly cautious... It took me quite a long time to chase it but as I went, I got more confident with the feel of the knife AND the wood! There's a really physical difference between the early and late wood, which I found to be a VERY big help!!
I also chickened out and used the drawknife for the first few rings, leaving the last ring to be done by scraper as I felt more comfortable. Didn't want to risk cutting into it with the drawknife.
Keep the edge sharp! I preferred using a drawknife to a spokeshave as the shavings can get stuck in the gap on the 'shave.
Best of luck