Hi!
I just auditioned for the Castle and am now a member, so here is my advice...
Number 1, do not do any flourishes. In my opinion, there is a high chance of messing up, especially in the environment you will be auditioning in. Also keep in mind if it does not add to anything, then it subtracts. In the audition, you are trying to impress the judges with your presentation, composer/confidence and magic; Coming from watching a few people using flourishes in their acts last month, they either dropped the cards or looked like a complete fool.
(I apologize, I am very blunt at times)
Number 2, if you are doing close-up, do not act showy. You should act cool, calm, collected and confident. Close-up magic is an art-form and should be presented as such. Furthermore, acting showy may give the impression to the judges that your are more cocky then confident.
A few more tips:
Construct your performance around you and who you are as a person/magician. For example if you love to skateboard or play basketball, find some one to work that into your act, setting you apart from everyone else, showing just how creative you can be. Along the same line as setting yourself apart, you may not like what I am about to tell you...DO NOT DO COINS OR CARD TRICKS! I truly mean this. Just this past audition, I did a cups and balls routine while the other 30 or so people did card tricks. From the judges perspective, after the first 5 card tricks, they start to blend together and look the same. So if you really want to set yourself apart, do cups and balls, rope magic, etc...
I would show up at around 11:30, park and you will most likely be directed to wait in the Inner Circle. You will then be taken to a side entrance where you will be asked to fill out an application. This in in my opinion is very important time to be alert and on your feet. Try to be first in line and turn in your application first since since sitting around waiting for 2 hours to go is not the best on the nerves. They are dead serious on the 5 minute rule so make sure you do not go over, even 1 second.
If you get called back for an interview, do not take this as a good or bad sign. I know people who were not called back for and interview and got in while people, including myself, got called back for and interview during my first audition and did not get in.
I think the most important thing is if you do not get in, but the criticism in your letter is very minimal or if they makes comments along the line of "your magic is strong, but you need to clean up your act a little", do not get down on yourself. In speaking with a judge, this is your final test per say. They are basically telling you that you are right there, but want to see if you are able to deal with rejection, stay committed for six more months and come back showing improvement.
I hope this helps, best of luck!
-Ryan