For me it’s driving while under the influence. If you couldn’t tell, I like me some ganja. However I have long since held the belief that it is utterly insane to drive while under the influence of most substances, with maybe nicotine and caffeine being the exception. All too often I see other stoners smoking and driving, which I simply can’t fathom. I’ve only operated a vehicle once under the influence and it was just to move a U-Haul around the block to a different parking spot, which was such a scary experience while high that I refuse to even consider getting behind the wheel again while high.
Pillow shading and what I refer to as “dull shading” where a person just exclusively uses pure black to shade. The former can look good in certain situations but otherwise looks a bit odd, the latter can make a picture look dirty if they’re otherwise using bright colors.