I am running a scenic flights day at the end of the month at our local flight school.(Full AOC).
If you have an AOC your operations manual should detail how you are to conduct pleasure flying and you need to comply with that. In particular if passengers may be boarded with the engines running, a dangerous practice in my opinion unless very carefully supervised.
The biggest danger are children, some of whom have been brought up to run off anywhere without supervision. Adults should always be holding young children's hands while walking to the aircraft and parents need reminding of tbe dangers of propellers.
You dont say what aircraft you are using but aircraft with sliding canopies can be dangerous and on no account should passengers board these aircraft with the engine running as it is possible to fall forward off the wing into the prop.
Ive known of a waiting child to run out to a returning aircraft and run into the prop in front of her father so the dangers exist on the return as well as the departure. Strict handling of passengers is essential at anytime they are airside.
Aircraft should always be positioned so that the path to and from the door is away from the propeller area and passengers need just as much supervision leaving the aircraft as boarding it which should be done in separate waves