Balsamic Glaze

I think the cheaper balsamics are a great way to go, but I don't like adding sugar to them. Reduce the vinegar slowly on its own until the bubbles start to get very small, and that's usually enough to get a syrupy consistency to the reduction. The glaze will be thinner when warm than when it cools, so keep that in mind when you're reducing. Also, the reduction will go from perfect to burnt in a difference of 30 seconds if you boil too fast, so slower will give you better control.

I would reduce half red wine half balsamic. Will yield richer flavor.

Agree with mr vittles ...equal parts balsamic and brown sugar, simmer for 30 minutes

Glaze or sauce? A Glaze for the asparagus? A sauce for the polenta? Try reducing cheapo balsamic with a bit of brown sugar. That works for me, when I just want a quickie balsamic reduction.