This is one of many food-conserving and thrifty tricks I learned from my parents and grandparents: making a salad dressing from the dregs of a mayonnaise jar. I was pleasantly surprised to see it turn up in a You Tube video. Maybe you'll find it useful, perhaps it'll give you some ideas or motivate you to post some similar tricks you use.
https://foodwishes.blogspot.com/2013/08/the-old-empty-mayo-jar-dressing-trick.html
And here's the short You Tube version in case you're the impatient type:
https://www.youtube.com/shorts/987oZ1MM5w0