LPT: After assembling IKEA furniture, tape the key to the underside so that you can easily find it in the future, if you need to tighten screws or disassemble it.

My desktop chair's armrest was coming loose, so I looked under it to find out which screw needed to be tightened. The original key that I had used to assemble the chair was taped to the underside, making it quick and easy for me to tighten the screw.

Funniest thing was that I had completely forgotten that I had done it, and was stunned at how smart of a trick it was