My maternal grandmother wasn't much of a cook in her younger years, but after her kids were grown she faced her empty nest by learning how to cook & becoming something of a gourmet.
She had a very simple salad dressing recipe that was deelish. The family always wanted the recipe & it's been lost & found & lost again several times.
You can use any kind of salad oil & any kind of vinegar you like. Granny used generic vegetable oil & usually some kind of wine vinegar, red or white. Or you can mix oils & vinegars. I'd leave the sugar out if you use balsamic.
You can also use simple syrup or agave syrup instead of sugar.
Granny used to keep a cruet of the stuff in her pantry all the time. She never refrigerated it; the oil curdles if you do. I don't know how we never got food poisoning from it but I'd guess the acid from the vinegar, the salt, & the garlic oil kept down any harmful pathogens. Plus we went through it like water, so it didn't sit around.
It's nothing fancy at all, just oil & vinegar, salt, sugar, mustard & garlic. & somehow it's perfect for damn near any leafy green salad regardless of the flavor profile. Works great on an iceberg with tomatoes & bleu cheese, works just as well on arugula with shaved parmesan, or on a garden salad.