This is a question that every actor will have at some point in their career, and it is a very important question. The answer to the riddle of "standing out" in the industry might surprise you.
You can try and try for years to find out what it is or what you can do to stand out, but the reality is that the only true way to stand out is to be your 100% authentic self. You are never going to stand out to everyone, if you are standing out to everyone ten you are probably doing something wrong. There is no better way to stand out then to be yourself, because there is only one you, and there will only ever be one you to ever exist. The right people notice what is special about you.
When is comes to standing out in castings and auditions - sometimes its not the best plan of attack to go in and try to be as quirky, crazy and unique as you might think. Although people love interesting people, it is also important to remember that one thing the CD will be looking for is someone who can they believe other people on the set can work with! always keep this in mind, a professional approach is equally as important.