I have never understood store-bought salad dressing.  Making salad dressing is one of the easiest things you can do in the kitchen, plus you will almost certainly use better ingredients than even the “natural” and organic dressing brands.  Who has even Xantham gum in their kitchen?
Homemade salad dressings don’t need to be refrigerated unless you are using dairy products in them.  Vinegar and lemon juice are both natural preservatives, which makes you really wonder why store-bought dressings contain additional preservatives.
Unless you are making an Asian style dressing and want a sesame flavor, don’t bother using any oil other than olive.  The reason store-bought dressings substitute other oils is simple:  they are cheaper.  But they also have less flavor.  By making your own dressing, you can spend more on good ingredients and still save money.
All four of the dressings below are perfect for dressing a salad with the romaine lettuce in your box today, and none takes more than five minutes to make.

Mustard Vinagrette:  Mix 2 T. red wine vinegar or lemon juice with 2 T. stoneground mustard.  Add 2-3 T. olive oil and 1 t. soy sauce.

For a creamier version, substiute dijon-style mustard for the stoneground.

Caesar Dressing:  Mince Green garlic to make 2 T.  Combine with 2 T. lemon juice, 1 t. dijon mustard and 1 t. anchovy paste.  Whisk in 1 raw egg and 4 T. olive oil.  When creamy, add 1/2 C. fresh grated parmesanplus salt and pepper to taste.

Yogurt Spring Onion Dressing:  Finely minced Spring Onion to make 3 T. Combine with 1/4 C. lemon juice and and 3 T. minced cilantro.   Let sit 10 minutes.  Whisk in 1 C. plain yogurt and 1/4 C. olive oil.  Season with salt and pepper.

Sesame-Avocado Vinagrette:  Mash 1/2 avocado in a bowl.  Add 2 T. rice vinegar, 1 T. lime juice, 1 T. soy sauce, and 1 T. toasted sesame oil.  Whisk until smooth.  Add 1-2 T. water to thin if necessary.