Here is a Food Network recipe for the balsamic. There are a lot of them that I didn't like. I would make a few changes, double the recipe and leave out the sugar. Also I wouldn't use straight balsamic I would use half red wine vinegar. I don't like my dressings too sweet, but if you do follow the recipe as is. I also buy a mild red wine vinegar, some of them are really strong. You can more than double it if you have a large family. I keep mine in a glass canning jar.in the frig. You have to pull it out a while before you use it as the oil starts to harden. Also shake well before using. I would use this on a spinach salad with crumbled bacon and red onion.
Here is a Green Goddess Dressing also from Food Network. I haven't made GG for ages and it sounded good.The only change I would make in this one is to use anchovy paste instead of anchovies because I like the texture better, but if you are an anchovy lover use them. I would use this on a mixture on interesting greens, with different textures and maybe some thinly sliced fresh button mushrooms. Again double the quantity if you want some to keep on hand but I don't think it will last a long. I was think this recipe has 4 fresh herbs in it which is kind of expensive unless you have them in your garden, but you could substitute cheaper things. I would probably use scallions instead of chives because I usually have those on hand. You could also use dried tarragon or a tarragon vinegar, which is a nice thing to have if you are going to make your own dressings, instead of fresh tarragon. The recipes I have used didn't usually have basil, so I'm leaving it out, because I think it might overwhelm the tarragon.
Growing your own herbs and making flavored vinegars are both good frugal ideas for making your own dressings. I make sure I have extra virgin olive oil and several kinds of vinegar in my pantry. I buy my evoo and balsamic at Costco.
I would like to make a lemon instead of vinegar dressing next and maybe find something new and interesting. Instead of buying bottled dressing try making your own. It's healthier and cheaper and tastes a lot better. Also if you make enough to have it on hand you won't have to make it at the last minute and you'll have all the convenience of a bottled dressing and you can have different kinds for different tastes.