From the Movie "I DO" by ABC Pictures
Reading and search to enhance my knowledge in the acting world and also to help continue manage and assist my actors brought to light this piece written but Jesse Daley an Acting Expert.
I decided to share this on my blog for the many up and coming actors and actresses who get lost when they enter the audition room. Hope you learn from these tips.

For an actor, the waiting room at an audition can be one of the most awkward places you will ever visit in your lifetime!  Or, it can be an incredible place of learning, if you choose to use the experience to your advantage.  Knowing how to conduct yourself in an audition waiting room is an important part of being an actor, and there are several things to do (and not to do) while you wait to be called in to your audition!
The circumstances that you may encounter at an audition waiting room vary greatly depending on the casting office that has called you in.  Some casting offices are very small, quiet, and intimate settings, whereas others are large, noisy facilities that are crowded with actors running all over the place!  Actors will likely be rehearsing their lines, and some will be chatting with other actors in the room.

1. Don’t Get Distracted!
Obtaining an audition in the first place can be difficult.  Remember, no matter where your audition is being held, you are there for one reason:  to book the job. Don’t allow anything or anyone to distract you from this goal.  And there will be distractions.  However, you can learn to avoid them!  When you go to sign in, you will probably see many other actors who look a lot like you do!  Some of my actor friends will tell me that this aspect makes them immediately feel uneasy, and it gives a notion of “competition” among all of the actors who resemble each other.  It is at this time that you may start formulating excuses in your mind about why you will not “book this job.”
In reality, the element of “competition” in this business is not something that you can become concerned about.  If you let it consume you, you will never be successful!  Yes, there will be actors that do resemble you, and there may be a lot of them, but you must remember that there is only one of YOU, and this alone sets you apart from the crowd, and in lots of ways eliminates the idea of “competition.”  
Embrace who you are, and this will bring about more confidence!  You have been called in to this audition for a reason, and it will serve you no purpose to compare yourself to anyone else in the room.

2. Smile
I like to make it a point to smile and say a brief “hello” to the other actors in the waiting room, without distracting them.  We are not in the audition room to make friends necessarily, however showing a little bit of kindness and flashing a smile is always appreciated!  Some actors have a very difficult time with the anxiety that can come with going to an audition, and smiling at another actor can help to calm them.  Again, do not view the other actors in the audition room as your “competition,” because that automatically creates a sense of rivalry.  As my friend recently wrote to me, “We actors have to stick together!”  We’re all in this together!

3. Always Show Respect

It should really go without saying, but sometimes actors don’t apply basic respect and kindness, and that’s not a good idea!  I was recently at an audition where a fellow actor and I had been waiting for quite some time to be called in for our respective auditions.  As we were about to ask the casting director about when we should expect to be called in, another actor walked in and asked me how long we had been waiting.  I answered, “About 30 minutes, so we are about to ask when we can expect to be called.”  Without hesitation, this actor walked right into the audition room and asked to begin her audition, which she was allowed to do – by-passing the waiting line.
I and the actor with whom I was waiting were baffled, to say the least!  We had a laugh about it, and I honestly don’t believe that the other actor (or the casting director) meant to be rude; I personally believe the actor was simply nervous!  Nerves make us do strange things, don’t they?  However, we must always be aware of our surroundings and show each other courtesy.  As I mentioned in my article, "It's All About Who Knows YOU," it will not be beneficial to your career by treating others with disrespect of any sort!
It should also be mentioned here that if you’re sitting in a quiet audition waiting-room and are able to hear other actors’ audition, I recommend walking outside in a hallway if possible.  By listening to other actors in their audition, you may be doing yourself a disservice by further comparing their performance to the work that you are going to shortly do!  This will also make you more nervous!  Speaking of the hallway, the use of a smartphone in an audition waiting room is very distracting to actors, so if you must take a call, it is best to be respectful to your fellow actors and step outside.

4. Relax - and Trust Yourself

There are many reasons why actors become nervous while in an audition waiting room, but you must train yourself to avoid giving into your nerves and avoid making any kind of excuses about why you will not “book the job.”  There may be instances, for example, where another actor in the room has previously met a casting director at a casting director workshop!  Just because the casting director may personally know that other actor, and not you, it doesn’t mean that you have don’t have chance of booking the job.  There are many factors that come into play when a role is being cast, and many of these factors are largely out of our control.
Trusting yourself and trusting your choices for your character ARE within your control.  I have found that simply trusting yourself is a key factor in having a successful audition.  While you are waiting to be called in, do your best to just relax!  Doing some simple breathing exercises helps a lot.
It is understandable that you might be nervous to go in for an audition, as auditioning is a vulnerable experience!  However if you just try to be yourself, and know that you are prepared for your audition, you will feel more at ease. 
Also, don’t worry so much about going over and over your lines.  Trust that you have already put in the work for this audition, and trust that you will do a great job.  When you are in your audition, if you do “mess up” a line, it’s no big deal!  Go with it, don’t ever try to stop and re-start your audition unless you’re directed to do so.  We are all human, and humans make mistakes.  Sometimes, going with the flow of a mistake can help get you a job!
Los Angeles acting coach Carolyne Barry often uses the phrase, "Mistakes are Gifts," and it is completely true!
It’s all about being YOU and being REAL!

credit: acting.about.com