Anthony Haynes writes: If at all possible, arrive in the room well before the session is scheduled to start — preferably when the room is empty.
Work out where you will stand, where you will sit, and where you will place any resources that you will be using.
Store your bag, coat, etc. where there is no danger of anyone tripping.
Check that whatever technology you’ll be using — for example, microphone, computer, and projector — is working.
Check that the lighting is appropriate and that you know ho to control it.
Check the acoustics — ask someone to help you by sitting in various locations in the room.
If you have a jug or bottle of water, plan where you will put them so that they’re within reach but unlikely to be knocked over.
Doing all this before your session starts will both give you confidence and make you look professional.