During a recording session, there are many small details that can subtly derail the ideal flow of the work at hand. Outside of the technical end of capturing music, I think we all bring other habits or routines with us that define who we are while in the studio. These are things we might not consciously know that we do. Below are my quirky little behaviors. If these are self-imposed rules, then I'm sure I bend a few of them occasionally. But remember: these describe my actions only. I am not asking anyone else to abide by them; nor am I criticizing others that have differing practices. That would be foolish. Rules are for jerks.
I don't play music by other artists that might possibly be inappropriate in some way.
I never wear band t-shirts.
I'm here to record the client. I am wary of coming off as if I prefer some other artist, or style of music, and don't wish to be working on what's happening right now. If discussions lead towards outside music like, "Hey, how did the strings on that Carly Simon song go?" then, by all means, I'll pull up a track and listen. Otherwise I won't subject clients to what they may perceive as my preferred taste (or your intern's bad taste) and possibly alienate a client. But when I know my clients well, playing music we all enjoy can be a great way to unwind, get perspective and talk about new recording ideas. On one session we even played that first Chickenfoot album over and over for comedic relief. (Apologies to Chickenfoot producer Andy Johns, Tape Op #39.)
I don't talk trash on other artists I have worked with.
It's pretty obvious, but if you're telling your client how crummy yesterday's session was, they'll probably be thinking that you'll be telling tomorrow's client how crappy they were. Maintaining and building trust in the studio is important.
Make coffee.
I have to explain that for many years I was the odd-man-out engineer who didn't smoke or drink coffee. I still don't smoke (though I envy those smoke breaks that others always seem to get) but I did begin drinking coffee in my forties. I'll make a pot and have that ready before the client comes in. After I ascertain whether or not my clients drink coffee, I then remember their preference. That way I don't keep offering it if it's not needed. I make sure that we have coffee and brewing equipment on hand (thanks to Stumptown Coffee for hooking us up) and I never demand break times to "go get coffee." If the client wishes to do so, and wants to pick me up a cappuccino, that's fine. But it shouldn't be me asking!
Bring my own food.
Here's a similar situation. If you haven't worked out specific meal breaks, then bring something you can eat while punching in. Sandwiches, canned soups, nuts, fruit, salads or leftovers work well. On day one of a longer session I bring in extra snacks and set them out for the band/artist. This can create a great situation where we all start bringing in things to munch on. There ain't nothing better than two weeks of sampling gourmet potato chips.
Never discuss money or rates during the session.