I make many kinds of vinaigrettes by just mixing a little EVOO and vinegar (sometimes white wine vinegar, red wine vinegar, rice wine vinegar, or apple cider vinegar). Putting in something to help emulsify the oil & vinegar is good - like a dab of dijon mustard or even a dab of sour cream if you want it a little creamier. Then just add whatever seasonings sound good. Sometimes I do more of a southwest seasoning with some chile powder or smoky paprika. Sometimes I use my Greek seasoning mix. Sometimes it's just dried basil and salt/pepper. I also sometimes add a squeeze of lemon or lime juice if I have it on hand.
Really I just wing it every time and go by taste and what sounds good. If I'm making a salad to have with dinner for my family, I try to mix up the vinaigrette and let it sit for a little bit while I make the other things and before I toss the salad. Having a little time (even just 10 or 15 minutes) for the ingredients to blend makes a nice difference.