Having trouble finding the proper output jack on the back of your computer for your headphones? Instructables user philip42 suggests using a school supply favourite, reinforcement labels, to help you find the right audio jack easier.
The premise is pretty simple. Audio jacks on a lot of computers and sound cards are hidden away without much of a label. Instead of making it a guessing game, a brightly coloured loose leaf reinforcement label like this will draw your attention to it and the labels fit perfectly over the standard 3.5mm audio jack. The basic premise can be applied to pretty much any port and the raised sticker can also help you find it in the dark.