Attire for Life's Moments

I was originally going to simply write about what to wear in a interview, but that's kinda short and sweet. But it can also be confusing. Cause what you wear in an interview and what you wear when you start working there can be so different. I also want to get an idea of what everyone else thinks. I feel like I don't go on interviews that often enough to be all high and mighty about it. But then I see some people before an interview or their first day of work or an outing with co-workers and think to myself, "Really? You thought that was appropriate?"
I know I'm not the only one to think this. There just have to be more people who are thinking to themselves that maybe their should be a little handbook on these things (there might be one already). But its not just what is appropriate and what isn't. There is also the whole, "We are artists...yada, yada, yada." Casual attire at work is usually a t-shirt and jeans. And everyday seems to be Casual Friday. So what are we supposed to wear for events pertaining to our professional life? Let me know. Comment about this, pretty please. :D
Let me, and everyone else for that matter, know what is appropriate for the work environment, interviews, after work activities, company mixers, studio parties, etc. If you can think of any events where you've thought "Hmmm, is that too racy?" or "Should I dress up?", please, I want to know your thoughts. I have my own, but I want to see what others think in the comments. This way I can take examples, too.