From: Linda McCartney’s Home Cooking, p. 150
This is a good base for a dressing that can be varied well. Personally, I like dressings to be quite sour and not too oily. So I would reduce the amount of oil to 2 tbsp of olive oil and omit the vegetable oil. Working with a blender improves the quality of the dressing as the oil and vinegar are worked together very well to have (and retain!) a creamy consistency. Here I would recommend adding some water to the mix before blending.
My favourite variation from Linda’s book is adding some curry powder for an unexpected and intersting taste variation.
I also like adding some (plant-based) yoghurt, agave syrup and mustard to the dressing.