Referees should have full coverage on obvious situations in their primary. A shot is an obvious play – always! The correct way to referee a shooting situation is to use a 1-2-3 technique for shooting situations. When used properly this technique provides the details for possible foul or fake call. The action need to have contact to be illegal.
a. Referee defense all the time.
b. Check the play in following order: 1. hands 2. body 3. feet (landing).
c. Stay with the play until shooter has returned to the floor.
d. Only then turn your attention to ball & rebounds
Taken from: Fiba’s Manual for IOT, august 2020