Always STOP! And think about what you're doing.
From my experiences and my peers (who shall remain nameless)
Personal
* Never dump a bag of rice hulls into an auger
* Always remember to turn your kettle on BEFORE you reach targeted kettle volume
* Never stick your head into a manway of a tank that has recently been purged with CO2
* Always remember to turn off the water inlet valve of a kettle when you walk away from the brewhouse(especially when there is already preheated hot water in it....especially if the brewhouse exhaust fan isn't on... especially if the brewhouse door is wide open...especially if the fire department has installed detectors that light up quick when steam hits them!
Peers
*Always make sure you've turned your heat exchanger on before knock out.....especially if you don't realize that your wort temp in your fermenter is 200 F....and especially if you've already pitched your yeast! (times 4!)
* If you are priming your cask beer with sugar, make sure to add it into the cask before you've hammered the bung in...especially if you've already filled it with beer
*When purging wort through a hose on brewday from your heat exchanger to the fermenter, make sure the wort that is being purged isn't from yesterday's brew
Cheers,
Mike Roy
Brewer
Franklin's Restaurant,Brewery & General Store
Hyattsville,MD
Franklinsbrewery.com
@franklinsbrwry
facebook.com/franklinsbrewery
Franklinsbrewery.blogspot.com