Have for many years (with 5 man crews) used the BJ to handle the play clock and to signal when there is 10 seconds remaining (arm fully extended straight up), then at 5 seconds (drop arm - fully extended out to side). We now avoid any verbal signals so as not to interfere with any team (A or B) signal calling. Most of our games are MA HS games (NCAA rules) but last couple of years we have been doing some RI HS games (NFHS rules).
What other play clock signaling mechanics are out there and are there specific "recommended mechanics" for NFHS games?