1) How do you structure auditions? (and specifically, what works for you when meeting/testing an auditioner for the first time)
Depends on the production. Is this a project you hope to go SAG Low Budget or as non-union? If you go union, the rules change up since you need to give union actors and extras prior consideration, though it doesn't exclude non-union. For some student productions, they get special SAG student guidelines. Most indies go non-union.
What is the nature of your project? Do you have specific looks you're going for? Often CDs will group actors based on attributes pulled from the script. If you need a 20 yo African American, you can screen out the 40 yo. Caucasian to a different role. However, if you have a strong actor, it can sometimes lead to a script re-write.
If you are casting for a large number of roles, it is often best to have readings clustered. So if you have a guy and girl, you pair them up and watch them interact. You can then call back and match up the two or three guys and girls who performed best individually. This matching can often cut down casting time.
Some don't like to have readings from the actual script but invite actors to provide their own monologue. I don't like this because it doesn't give a good feel to me of how they interpret the character. (I'll touch on that in your next question.)
I usually like to have them improv from a description. Largely because it gives me a sense of how they do in creating an illusion. I will then make a couple changes. This allows me to see how well they can take direction. I've been on projects where we have viewed videos created by actors. I still prefer in person auditions or auditions over Skype.
2) How much do you like to analyze a character... do you try to answer Uta Hagen's 9 questions, and think up a whole backstory, for example, or do you leave that all to the actor's domain? Do you instead just consider objectives, targets, tactics?
I like to see how the actor interprets a character. Then I will sometimes change an element to see how the actor adapts to the change. It gives me a sense how they would respond in other situations. Often the actor works with the director and other actors to develop a character. I don't recommend giving the actor the whole script, but pull out a segment that highlights the character's range.
When you go to direct, you will want to sit down and develop the motivations for your character. I don't go into deep backstory. Your actors will do the same. At the reading (I always recommend a reading), you can go through with your actors and decide on motivations. I'm sometimes surprised and impressed out how an actor interprets a character and incorporate that. I might ask a character to read the dialogue as if they just came from a party or just learned a friend was in an accident to see their emotional range and expression. Does the actor have the look and deliver a believable performance for the role for which s/he is auditioning?
3) Question for the actor: how have your favorite directors worked with you, and are there any good acting forums out there I could check out? Thanks!
I look for feedback on delivery. While actors work on developing a body sense, it's still hard to see what the camera is seeing. Actor's directors are fun to work with, as they've been in front of the camera. Writer/directors tend to be harder to work with since they tend to think their scripts are gifts from God. They're picky about lines. Usually the ones that want you to say the stupidest drivel. Most have never acted so they don't appreciate that nine lines of dialogue isn't appropriate for a casual scene. Acting and directing has influenced my writing style. There are acting divas who give all actors a bad reputation. There is a difference between suggesting something based on the character you've developed as an actor from "Well, this is the way I want to do it." Most actors respect the director's final say. Directors who are indecisive are equally problematic. More so for the behind-the-scenes crew who need to make multiple shots. This can also affect the actors. Having bright lights on you and repeating the same lines and actions multiple times comes with the territory. However, about take 18 of almost identical content you start to fade a bit. They also tend to run behind. 'Actor directors' - actors who are directing while acting-can be interesting. They constantly are running back and forth to the camera to see if they captured what they wanted. This is a case where the director needs to turn over responsibility for that scene totally to the the DP after having gone over the shots. The visual director is all about cameras, angles, movement and lighting. While they work with the actors, they tend to choose professional actors who always deliver solid performances. I like working with them too as an actor. As crew, they can be very demanding though you master your skills.