I think I'll collect all of these to remind myself I'm not the only who who does this. I can add a few:
Thou shalt always have a sharp seam ripper at hand.
Thou shalt always have a bandaid at hand (when I stick a pin in my finger/toe etc).
Thou shalt not cut fabric that was not intended to be cut (last time broke this was on my cutting table when I accidentally put a 1/2 yard on top of some already prepared squares and cut a nice strip - out of the 1/2 yard AND the squares)
Thou shalt always have enough thread of the same color to finish the quilt (especially if you are hunkering down in the mountains before a snow storm...)
Thou shalt always clean thy bobbin case...
And my favorite
Thou shalt not drink spirits before quilting. (I've not done this but a friend of mine did. Her quilting was converted into a crazy quilt... nuff said).