Mental math.
Apparently, I’m some sort of genius because I can figure out %'s, know that rounding to get approximations is useful for real-world applications, etc. Like figuring out the 9.25% sales tax on a $199 purchase - a person I know started typing on their phone to get the number and I’m saying “A little more than $18, right?” Cue evil look and “I’m not a math whiz like you” comment. :dubious:
Bzzzzt–see post #15.
When you go to install a new motorcycle battery, put a little wad of paper or tape under the loose nut. It will hold it up to facilitate threading and keep it from falling out.
Do not go out & buy spray glass cleaner.
Buy sprayer bottle & a one gallon jug of white vinegar.
Dilute 50/50%.
It is also a decent spot remover, & freshens sneaker smell.
Similarly, if you grow leeks and just want them big enough to cook- not exhibition size ones, don’t dig them out when you want to harvest them. Cut them instead, leaving the roots and an inch or so of stem (only a bit longer than the end you’d chop off and throw away) in the soil. They’ll regrow over the next few months- you can even harvest them three or more times before they bolt if you’re lucky.
Actually ibuprofen and aspirin are the best thing going for sunburn, believe it or not. They blunt the pain, and they’re anti-inflammatory as well.
Oh derrr! Paper towels, good idea. The one time I had to use this trick, the washing on hot worked very well in taking the wax out before it even got to the dryer though. And hopefully getting wax on one’s carpet isn’t a common occurrence. 
External, internal or placebo?
When I am trying to compare two printed pages for any dissimilarities, I stack one page on the other and then hold them up to a light. It becomes pretty easy to see if there is any additional text.
Pfft, I don’t need to look at post #15 now.
The mental math I did for that was taking approximately 10% of $200 - somewhere around $20. Close enough for me. 
This is a useful trick:
Rounding to easier numbers to make quick tax (or tip, or whatever) calculations can give you a ballpark figure of what you’re looking at.
This is not:
This is just a post that says “I can do math in my head.”
Naw, it’s more a post that said I didn’t read the OP very well. 
My second of the day, in fact (“Amazing BS facts” is the other.)
Internal. I got sunburned pretty good as a kid once, and my mother called the dr. to see if there was anything out of the usual folk treatments, and he suggested aspirin.
I learned about the miracle of vinegar in a thread like this one, here on the Dope. I now keep a spray bottle of diluted white vinegar near my sink, and the vast majority of the time it is all that’s necessary to keep my kitchen clean. It also works on dishes, and is similar to dish soap in the way it can cut grease.
Mine: Before bed, put a little dab of toothpaste on any blemishes you might have and in the morning the inflammation will be quite reduced.
Also, I don’t know how much of a ‘‘tip’’ this is, and I’m sure it’s pretty commonly known among athletes, but I recently learned that ice baths are incredibly effective at reducing pain, swelling and long-term damage from a muscle tear/sprain injury or really any muscle aches and pains you might have. It’s as horrible as it sounds - run water as cold as you can, dump in ice cubes, pull on a sweatshirt and sit in a freezing cold tub for 10-15 minutes (not longer, or you could literally die!) Do this as soon as you realize you have injured yourself. It’s an… um… great opportunity for mindfulness. The first time is the hardest; I’ve found that filling it up and then climbing in at once is the best method. But the effect is miraculous - I pretty much did a week’s worth of healing overnight, or at least it felt that way.
Nevermind.
A couple of screwdriver tricks-
If you’re going to unscrew a sheet metal screw that’s likely to be stuck, twist it a bit tighter first to break it loose, then unscrew it. The classic place for this trick working is on chrome headlight bezels.
If the screwdriver has a square or hexagonal shank, you can put a crescent wrench on it for more torque.
when doing either of these you need to put your body into it and press the driver hard into the screw; if you don’t then you will tear up the screw head.
The sooner you take them, the better, too. I carry a bottle of ibuprofen with me to my LARP games, so I can hand them out to whoever looks burned at the end of the game. Waiting until they get home–which may be hours later–gives inflammation time to set in, and makes the burn more painful.
And make sure you’re using the exact right screwdriver.