As a guy who does microsurgery pretty frequently, if you get under enough magnification, everyone has a tremor. The biggest thing you can do is to work on stabilizing techniques. How to position your hands, and how to hold instruments a little differently to try to minimize that without effecting maneuverability. Keep in mind that while small motion is important in microsurgery, you really don't need to be able to fully pronate your wrist, for example (simply because you're not working in a big enough field for that to be relevant). Most importantly (and I cannot stress this enough) release the tension in your shoulders, arms, and back, and BREATHE. Most students (myself included) subconsciously hold their breath when they're working under a microscope because they're trying to control their tremor. That's the opposite of what you want to do, and your tremor will get worse. Finally, take a minute or two pause when you can to recenter your thoughts. That's helpful when you're at critical points in the surgery.
It's not so much about fighting off the tremor, it's about making changes to minimize it. This is true for microvascular, ear surgery, and probably also for whatever you're trying to do.
