I've been crossfitting since 2008 and along the way I've learned some personal No-No's and some Must Do's. Everyone is different but here are a few "rules" I personally live by when it comes to Crossfit:
NEVER say "that looks easy." The minute the words come out of your mouth you can guarantee yourself a good ole ass whoopin' wod that will leave you in a heap wondering what happened.
ALWAYS check your ego at the door. Someone is always going to be faster, stronger or better at something. Yes, you may very well be a badass, but you may not win every single wod, lift or skill. Even the winners of the Crossfit Games didn't win every workout. Put your big girl/boy undies on and deal with it.
NEVER, EVER add up the reps. It is much easier to bite off and chew small chunks at a time, rather than suddenly realizing you're about to do 250 squats. Trust me, don't screw with your mind that way. Leave the math alone.
ALWAYS be coachable and listen. I don't care how seasoned you are in this sport. You can always learn more.
NEVER quit. It speaks to your integrity. Barring serious injury or broken bones...keep it moving. You can curse or even cry if need be, just don't stop.
If at all possible, ALWAYS go first. There is no way in hell I want to sit around and see the anguish and life sucked out of someone right before my eyes…on a wod I'm about to do! No thank you. I'll go first and be happy as hell cheering you on in your pain cave afterward.
I have others….but let's share the wealth here. What have you learned or put in place as a "rule" for yourself. They can pertain to crossfit in general or CFNA. Let's hear it.