One of my favorite, easy gourmet tricks is to make balsamic vinegar reduction. Its quick, cheap, fun and can really make a difference in your meals. The first time I had balsamic vinegar reduction was served over pumpkin ravioli. Since then, I've used it on roasted root vegetables, and I suspect it would be delicious anywhere you would consider using regular balsamic vinegar (on strawberries, over salad, with avocado, etc.).
To make it, pour some balsamic vinegar into a pot (aim for about twice as much the final volume you would like in syrup), then heat over a medium flame, stirring occasionally, until the vinegar is reduced to a syrup consistency. This doesn't take very long. Some people suggest various additions (brown sugar, salt, butter) as desired, but I like the syrup as-is.
Have you tried making balsamic vinegar reduction before? If so, do you have any tips or favorite variations?