Me and my friends do the same thing.
1) First hit goes to who ever weed it is.
2)you yell out "deuce" if you want seconds on the blunt
3)"Tres" is what you say for the third hit
I usually only smoke with 1 other person or 2. So we never really get past 3. And if we do have over 3 people first hit goes to whoevers weed it is. and then we just pass it around I've smoked with like 6 ppl but we werent really in a circle we were all spread out sitting on chairs, couches, tables, and stools. We just passed it around since we had 3 fat blunts that day.