I was going to mention a few points myself that have already been mentioned...the bag of crisps thing has frightened more than a few pilots over time. Not as much as a Fouger Magister pilot I was talking to whose shaving foam exploded in the non pressurised bit on the shelf behind the back cockpit...
The microphone issue is a good one...I've hit the microphone with the bottle/can several times. All too easy to forget it's there!
Chewing gum...I've recommended to several people that gum not be chewed while flying, in case of sudden turbulence or suchlike.
Sugar? I once bought a box full of doughnuts down in Key West to eat as breakfast/lunch on my flight back to Winter Haven. I managed about half. The rest took me another 2 days.
Paul