Adding to 1, I find that it is very helpful to have kept track of the things you did for the company as they happen as it is very easy to forget even important

Adding to 1, I find that it is very helpful to have kept track of the things you did for the company as they happen as it is very easy to forget even important things along the way. I have a script that grabs my commits that week and throws them into a templated document. Each week I edit that document by grouping the commits in a logical way, adding things that wouldn't necessarily be captured in my commits, and then cleaning it up to make a reasonable and concise report of what I did that week. Then, at the end of the year, when it is time to discuss adjusting your compensation, gathering all of the data points is as simple as condensing your weekly reports into a single document.