Making your own salad dressings isn't that complicated, and can save you money in the pocketbook. At our shop, we make "concentrates" of various dressings, freezing portions of the recipes before we add the extra oil.
You can check out my sample recipe for Lemon Caper Dressing, again, from my
pccusine.com blog. I've also got recipes in my cookbook,
From the Land of Milk and Honey.

Popular dressings from that book: Caesar Salad Dressing, Italian Dressing, and a Sweet n Sour dressing, made easy with a well-seasoned tomato paste mix. With the seasoned tomato paste on hand, you're close to throwing the whole dressing together, and you can save leftover seasoned paste for your next salad, mixing it up fresh and easy. The seasoned tomato paste keeps well, having plenty of spice and vinegar to preserve it. It comes in handy in other recipes too. I love using it to make home-made Thousand Island Dressing, and I add a touch to meatloaf and soups, for instant flavor.