I started to lay out a lengthy description of ball handling operations, but my experience was with crews of 7, and I suspect crews of 8 is significantly different, with the C handling the ball so much, and being behind the NZ. So I'll just make some general comments.
Be focused and pay attention - essentially, be ready to replace the game ball after every down. When moving to make a replacement, hustle - don't 'hurry,' but hustle. With the 40-second play clock, you simply have to hustle, to get the ball spotted efficiently (by 32 on the play clock).
The convenience and efficiency of ball replacement is highly dependent upon the ball persons. At the FBS level (crews of 7), we often had as many as 5 ball persons PER TEAM. One with each sideline guy, and a "runner," to keep the number of balls balanced on each side. If you have that many ball persons, and you work with them effectively, ball handling can be very smooth and efficient. You may not have the luxury of 5 per team. You may have as few as 2 per team (one on each sideline). Regardless, be friendly to them and treat them with respect. Tell them how much help they are to you and your crew, and how much you appreciate their effort. Ask them to hustle, pay attention, and be ready after EVERY down, to get a replacement ball into the game. Hand the ball to each other as much as possible, but short, underhand tosses are fine. Ask them to stay off the field, unless you direct them to come onto the field to retrieve an 'old' ball near the sideline (while you are getting the replacement ball into the U/C). For their safety and your safety, ask them to stay at least 6 feet off the sideline, unless they are in the act of sending or receiving a ball to/from you. If you don't have a "runner," tell them that you (the crew) will do your best to help keep the balls balanced, but there may be times when they will just have to run around the end zone to the other side to retrieve/deliver a ball for that purpose. Ask them to be ready immediately after the coin toss, and be back on the field and ready to go before the second half K/O. Tell them to keep any comments to persons on the opposing team to a minimum; if they have an issue with opposing team personnel (including their ball persons), let you know and you will handle it.
And don't mess with the air the frickin' balls.
Good luck!
Robert