I started using different colors ever since a controversy when my dad was scoring a CYO season-ending tournament game. I have a set of 8 colored pens I rotate and I also switch the direction of my hash marks at the half, so that first half fouls are marked / and second half are marked \. The only exception is offensive fouls which I circle.
I've also begun to put a bar ( | or _ if the AP goes up to down) at the end of the AP for the quarter so I know whose ball it is to start the next one.
Even if the team foul count goes above 10 in the first half, I'll use + signs to indicate each foul above 10, just incase there is an issue with team fouls later in the game.
At MS games where we have a student scoring the home back, I make more of an emphasis to ask them about the foul count/time outs remaining just so there are no surprises in crunch time.
{NBA Aside} I will also use a triangle on the team foul count to indicate the first foul in the last two minutes. {/NBA Aside} I still find myself doing this even under NFHS rules.
