I read the threads here and see that stance angles vary from person to person. I'm setting my son's board up (I ski) who is new to this. He's 17. 5'10" 180ish and regular stance. This is his first year since he was about 8 snowboarding. The guy at the shop mounted the bindings and showed me all the doohickeys and how to make adjustments. My son wasn't there at the time so as far as setting the angles, we left it at - they are easy to adjust without tools so just play with them.
If I learned anything from skiing, it's that slight adjustments can have big effects. So to get him in the "ball park" I had him put on his socks and run and slide on the floor like you do to figure out if you're goofy or regular. Then at the end of the slide I had him freeze and matched the angle of his bindings to the angles of his feet. He ended up with the front foot at 20 deg (towards the front) and back at 5 (towards the back). Or something close to that. My reasoning was that the stance he ended up in is the stance his body wants to be in and does it naturaly.
Is this a good way to start or are beginners better off starting at a "beginners" setting and working towards a more advance setting from there? If so, what would that be?