I begin with a complete disassembly, followed by cleaning. Then the rusty bits are soaked for a few days in rust remover while I attack the rest. That starts with either a wet-sanding with whatever grit paper is appropriate, from 320 to 800, or, if the corrosion isn't too bad, I have success with a fine painter's scuff pad (gray) used with a scuffing compound. Then a single pass with aluminum polish to give a sheen without trying to look like chrome.
Here's a look at a right-side set fresh off the project bike (left photos) and a finished example (right).
(click on an image to enlarge)
As an alternative to painting the master cylinder, it can be left bare metal (as they were on the later VFRs) and rubbed with a metal treatment, like Corrosion X, as seen here on Project 14. Also shown is a polished brake lever.