You are right to be primarily concerned with what happens inside the audition room. But I encourage you to extend your professionalism to the people and situations outside the door.
Singers don’t overtly try to get inside each others’ heads the way professional athletes do, but there are mind games outside the room. Most artists are fair-minded and collegial, but you will inevitably meet people in the waiting room who end up undermining the confidence of the competition in the process of trying desperately calm their own nerves.
Whatever the reason, if a singer in the waiting area is spouting off in a way that intimidates or unnerves you, figure out a way to silence the noise immediately. If it’s possible to leave his/her vicinity and wait in another area, do so. If you must stay there, hide behind your earbuds or engage in quiet conversation of a positive or neutral nature with someone else.
Develop one. Don’t leave any distracting details to chance.
Get the packing of your clothes and your music down to a science. Be sure you have worn your audition clothes (including shoes!) before and are supremely comfortable in them.
Don’t be surprised to find no warm-up rooms. We all do our best, but in most cities, the spaces we rent simply don’t have warm-up space available. Develop a strategy – singing in the car, lip-trilling in the elevator, whatever it takes.
Give yourself as much time as possible to get there, and have a deliberate plan for what you will do with the extra time you will have if you’re lucky.
You Never Know Who’s Listening
Whatever you do or say should play itself out as if the panel themselves were out there in the waiting room with you. Because very often, the anonymous-looking auditions monitor is closely affiliated with the company for which you’re about to sing.
And especially for a small company like ours, realize that the people holding the auditions are likely the same people who advanced the screening and application process. (In other words, pretending that “they” or “he” or “she” told you something that isn’t true won’t work. Because “we” are “they.”)
We’re not paying attention to all of this just to be punitive. If we’re considering working with you, it’s reasonable that we would be interested in your general level of integrity and professionalism – even when you think no one is looking.