Around the college, I've noticed all sorts of washing faux-paus by the college students that were never taught how to do laundry properly. At the school, they have a variety of Maytag top-loaders, and front-loading Neptunes:
compacting laundry into the washing machine like one is packing a suitcase for an extended vacation...especially in a top-loader, the clothes just sort of rotate around with the drum, instead of tumbling.
Dumping gallons of detergent into the machines to the point that suds wash over the top of the tub and onto the floor.
dumping all the laundry into the machine together without sorting.
not cleaning the lint filters in the washer or dryer
constantly pinging the router in the laundry room for status inquiries of the machines to the point that the machines can't handle all the service requests and the network crashes.
Leaning on the doors of the front loading W & D's while bending over, twisting the hinges, and causing them not to close properly....the particulary portly people are famous for doing this!
Washing one large, heavy object in a front-loader, so it goes out of balance during the spin cycle, making the machine dance and vibrate across the floor...and despite all the network requests, the out of balance machine is never tended to after it malfunctions.
Sitting on top of the machines that are not in use, talking to fellow students, all the while blocking their access while others are attempting to do laundry. Heavy people...please don't do this at ALL...it bends the lids up!
Here's some peeves outside of the college that I've seen people doing at home:
Using the dryer, when the weather is nice outside, and would dry clothing on the clothesline (Subdivisions that ban the use of clotheslines!)
Washing oily rags and work clothing in the washer without pre-treating the articles, and then cleaning out the machine after the job.
Over-washing clothes...if you didn't get sweaty that day, and you didn't get into anything dirty, chances are your clothes are clean enough to wear another day...I know it sounds gross, but it really isn't if you didn't get dirty! Save your favorite clothes, most of their wear and tear occurs in the washer!
Continuing to operate an appliance, despite the fact it is making unusual noises and/or poorly performing
attempting to dry solid objects like belts, purses, shoes, etc in a tumble-dryer
rapidly twisting the dial of a mechanical timer while the machine is running, rapidly sending it through all it's mode changes in less than a second or two
Leaving a machine running unattended, while nobody is awake, or at home.
installing washers on upper floors of the house, so when they leak or splash water, it leaks though to the lower floors and stains and damages the ceiling below and everything else below it.
HERE ARE TWO SAFETY TIPS I RARELY EVER SEE APPLIED:
Not shutting the water taps off after one has finished using the washing machine!
Not having a qualified technician disassemble and clean out the lint in a dryer (and the air duct) every so often, and waiting for the lint to build up till it becomes a fire hazard!