Pre made salad dressing can be really expensive and with a lot of pre-made stuff, you don't really know what's in it. With the exception of a fancier dressing like Caesar  most are made from very few ingredients and are made by a simple vigorous mix.

Salads can be a really easy but impressive quick dinner and don't need to resemble rabbit food. Go for an interesting leaf over Iceberg alone. Try a mixture of salad, beef and cherry tomatoes in one dish, think about texture when building your salad. And don't forget they are not just for summer. A warm winter salad of roast peppers and artichokes with some crumbled feta topped with peppery rocket is a perfect meal for these temperamental pre-Spring days.

A really quick, go to vinaigrette dressing is made up of a decent olive oil, balsamic or some kind of wine vinegar, mustard (I tend to use Dijon for a milder flavour though whole grain would add texture), salt and pepper. The quantities will depend on how much you are making but I tend to go with about 2 parts oil to 1/3 - 1/2 cup vinegar, teaspoon of mustard and a shake of s and p.

This is a great base to start working from, experiment with different vinegars or flavoured oils, add in additional ingredient like honey or sub some out like replacing the vinegar with lemon juice.

By mixing the dressing up in a jam jar you can give them a really good shake with emulsifies the oil and vinegar creating a creamy texture and you have your built in storage pot!