I used to work at a restaurant that had a prominent local realtor as a regular. Older white lady, her face was on billboards in the entire metro area (1+ million people) and she would come in, demand to be seated in the unused party room. They'd have the person in the nearest section cover her, splitting their attention between their normal tables and the one isolated patron (plus one dining partner sometimes), which often led to reduced tips from other tables as you were busy with her and their service suffered.

She always, always , tipped 1 (one) dollar.