Use nail polish to mark your keys

If you're like me, you have problems finding the right key for the right door. One way to resolve that is to get different colors of nail polish and paint the top of the key with them. I've done this so it's easier to figure out my house key from the key to the barn, or rv, ect. Use a different color for the different keys. Works great for those that are used a lot.

This is something I've always done; a very helpful idea

another way (the one I use) since nail polish tends to wear off when keys are carried in a pocket is to mark door keys with a notch filed into the handle part. So even in total darkness you can tell which key you need