Easy, cheap make-ahead salad dressing recipes?

Does anyone have favorite salad dressing recipes to share? I'm looking for something that I can make a lot of that will keep in a the fridge for a week or two. My go-to is balsamic vinegar, olive oil, spicy brown mustard, and agave nectar, poured into a jar and then adjusted until it tastes right. But that gets a little boring several days a week. I have all the basic oils and vinegars as well as some of the fancier ones (and some miso I could stand to use up, if there are any ideas for that), and I know there must be some great combinations out there that I have tried yet.

Thanks!

Cross-posted to vegrecipes