I use it mostly for descaling. Which means the kettle, now that we have a water softener fitted.
I empty the kettle, pour vinegar in until the top of the scaled-up area, and then leave it for a while. If the kettle was hot or there's not much scale, it takes about 20min, but if the kettle was cold or I have allowed a lot if scale to build up, it takes an hour or more. Then I pour the vinegar into a bowl and turn the kettle upside down in it to escape the rim and spout. When it's done I pour the vinegar back into the bottle. Rinse the kettle a couple of times and it's ready to use. I reuse the vinegar for descaling until it turns green.
I used to speak shower heads in a bowl of vinegar overnight to descale them.
It's supposed to be good for cleaning windows, but I found the smell unbearable when I tried.
Though excellent for deodorising! When a child has thrown up in the car, after I've cleaned up I leave a small bowl of vinegar in the car overnight. The following morning the car reeks of vinegar, but open the windows and within minutes there's no smell at all, not of vinegar or puke (or any other stinksome accident).
It's excellent instead of fabric conditioner when washing towels. Softens them a bit, without reducing absorbency. Don't leave any smell, and if used regularly, reduces scale build-up in the machine.