When cleaning the little rollers in your mouse, to get rid of the Nameless Horror that gathers there, do not drop the unfolded paper clip you are using into the guts of the mouse.
When trying to extract an unfolded paper clip from the guts of your mouse, do not shake it, as this will only bury it even further in the guts of the mouse.
When asking your colleagues if they have a small screwdriver, try not to be surprised that none of them do, even if you work for an engineering firm.
When folding a paper clip into a hook to remove another paperclip from the guts of a mouse, do not plunge it into the tip of your finger. Also try not to get smears of blood over the drawings you are working on.
Encourage your employers to invest in optical mice.