Use only bright-colored thumbtacks. Then when you drop one, you have some chance of finding it before you step on it in your sock feet.
Same with bandaids, bright neon colors so if it slides off your finger while you’re messing about in the kitchen you’ll find it in the soup/salad before you serve it. 
Every other time you put the box of raisin bran back in the cupboard, turn it upside down, so the flakes and raisins don’t segregate too much.
I know there are others I’ve thought of, but this is the only one that’s coming to mind right now.
If you have an ‘on demand’ hot water system, turn the hot tap on for rinsing your mouth out after brushing your teeth, then turn the shower on and less time and water is wasted.
I learned from watching a sitcom set in a restaurant kitchen that blue bandages are customary in commercial kitchens.
If you have a sound bar take a rubber band and tie the sound bar remote to the bottom of your regular TV remote and flip them whenever you need to change either the sound or channel, instead of buying a universal remote.
Put suet cakes in the fridge before opening them. Cold suet isn’t nearly as messy to handle as room temp suet.
When changing the batteries in anything, first take out the old batteries and immediately throw them away or put them on the other side of the desk/room/neighborhood. If practical, do this before you unwrap or unpackage the new batteries.
Years ago I got sick of discovering out of date food/leftovers in the fridge and having to throw them out. Now I record what’s in there with a use by date, on the front of the fridge with whiteboard markers. As they get used I clean off the listing. I hardly waste anything any more.
Not just batteries. I was trying to diagnose a computer issue, and had to carefully separate the possibly defective parts from the known good ones.
I had no counter space in my new apartment bathroom, so I started standing every tube on its cap. Suddenly, I had no more problems with the dreaded toothpaste squeezed from the middle or trying to get the last bit of soap or sunscreen out of the tube. I can only blame the manufacturers who printed the labels in landscape for not realizing it earlier.
No ladders inside the house. Ever.
When starting a fix-it project like plumbing, painting, etc., bring a cup or bowl…good place for screws, bolts, nails pulled from the wall, etc.
I have a fair amount of counter space, but don’t want to waste it on a dish drainer. I mounted a vinyl-coated wire shelf above my sink and use that as my dish drainer. Water drains into the sink. There’s another shelf above it for dried-food storage. (I used to work in a restaurant kitchen with extremely limited space and am used to making the most of what’s available).
Why not? How else would you change a lightbulb?
I know I’ve seen people doing it since I figured it out, but using chopsticks to eat Cheetos. Much cleaner.
I found out ladders being brought in the house always end in something or someone getting broken. Step stools can reach light bulbs.
If it’s higher than that it don’t get changed or dusted.
If you want to refresh the appearance of a porcelain sink, put some whitening toothpaste on a sponge and wipe it down.
To take a good photograph, find what you want in the viewfinder, focus, and then, once you have the image that you want, very slightly move the camera around in place until the image / lighting looks just right. Then snap.