I get paid peanuts at my job, but nonetheless worked my ass off this past year. I started three weeks too late to get a cost of living increase whereas my coworkers did. Sucked.
By the time appraisals came another year later, I was only offered a 6% raise, less than inflation. A few months before, I talked to my boss about benefits and a raise due to not having the same benefits as my coworkers (e.g. hourly when everyone else is salaried). It was still pending she says during our regular meeting.
So a week after receiving my subpar increase, I point blank told my boss I'm interviewing and am considering other employer who will pay me a fair compensation. I had negotiation leverage because my role is critical to our group. If I leave, it would seriously suck for her. She panicked and literally within the week approved a 9% raise, salaried. I made her sweat for a day before I accepted that offer, as if I were considering other options I didn't actually have.
Note: definitely helped that the other employer I said I'm actively interviewing with (which I was, but I'm not a good interviewer and they decided not to move forward with me) was affiliated with my s/o. Hence her panic that I'd definitely leave lol.