Another addition, (or tie in to one mentioned), if you get rejected audition after audition, it probably isn't good practice to ALWAYS ask the director why wasn't I casted this time each time you see him after an audition. If you make a habit of doing that, that makes you out to look like a complainer/whiner. After watching this, I realized I did this myself a few times and in my eyes, I was just asking in the sense of to get an idea of what I need to work on for the next audition. But the director may look at it as, "Sigh, there he goes again, asking again why he didn't get a part."
Yeah, I've actually heard from other directors that they hate getting asked that question, because typically the answer is something along the lines of "You didn't fit the part" or sometimes even "I don't know. You just didn't." Personally, I prefer the question "What do you think I could continue to work on?" This shows self-reflection and a desire to improve as opposed to just "I'm upset I didn't get cast and I want to know why." But my background is in Education, and I enjoy helping people learn. I always say I'm an educator first and a director second. Not every director feels this way though. I personally know a lot of them that feel that that is not their territory. Their job is to put on a show not help other people improve. Or they just don't know how to help people grow as actors. They're not educators, they don't have that kind of training. So, it can be a craps shoot asking those kinds of questions. I personally think it's okay as long as you approach it correctly, but actors need to be prepared for either no answer or an answer they may not like.