What are some of your favorite life hacks?

[Kurt]

I spent a lot of time in my past trying to think of the perfect place to hide a spare house key. I was always afraid that if I could think of a place to hide a key so could someone else.

Then one day it hit me when I was in a novelty shop (the funny kind of novelties not the adult kind). Fake dog poo. So I just cut a small slice in the fake poo, put the key in and placed in in the back yard (we had a dog) in a place I was sure we would remember where the fake poo was. I never felt so secure about hiding a key.