Advice for the 1st Year: Free Throw Violations

[ca_rumperee]

Hi persons! (zero gender-bias)

I'm looking for some advice on managing free-throw violation whistles/signals.
It seems that every time I am the lead administering free-throws, I have to do a mental summersault or two trying to figure out.. ok, white is shooting, immediate whistle if one of these two white jerseys go early, but delayed for blue... i'll use my arm towards the table for delayed, and my arm toward the basket for immediate...

sometimes i end up blowing the whistle on a delayed where the shot goes in... ack!

it all feels very awkward. i'm thinking that i will develop a concise system ultimately, but maybe i can get some insights from vets that will help me get there quicker.