The biggest thing you can, in my humble opinion, is to make choices predicated on a long term view instead of what is most convenient for you, in the next five minutes. It doesn't require you to code up some sort of amazing app, or dedicate your free time to open source, although both of those are great.

I liken it to the attitude people are starting to take with regard to other aspects of their lives, such as food and materialism. When I go to the store I know that I can save a few dollars by buying the absolute bargain basement produce, flown in from south america, taken from high intensity factory farms, or packaged up and made mostly out of HFCS. Or I could see what I can buy from local producers and from farms that prioritize ethically raising animals. It means my eggs cost 3 bucks more, and I can't have kiwi fruits in February. But wanting kiwi fruits right this minute, even though it is February in a northern latitude is the exact sort of attitude I am speaking of.

So how can you put this into practice? Well a few people have already made similar suggestions so some of this will be duplicating their suggestions, but I still think it is worth saying.

1) Use your own email. I personally like Fastmail. For $50CAD/year I get a great service. I know that I am paying for a service and am not the product. They are doing good work with the open email protocols that exist, and working to produce new open standards for the future.

2) Use Firefox. Do we really want to give a dominant majority marketshare in the browser market to a browser made by a company that makes 90% of its money through advertising to you? This isn't even some sort of rant about google being "evil", it's just a common sense decision. It wasn't a good idea back in the day to give dominant marketshare to a company who incentives were aligned against the web and towards desktop single platform applications, and it won't be a good idea to give that sort of power to company that is beholden to shareholders and makes it money through tracking and gathering data on users.

3) Delete your facebook account. I don't have a fallback here, but honestly I don't think you need one. Between messenging apps, smartphones, email and other communication tools, you will be able to stay in touch with people you care about. Facebook is not irreplaceable and I say that as someone who was in University when Facebook blew up. I am still happily communicating with all of those people.

4) In general, think about your purchasing decisions and who they empower and what the long term gain is. Shopping at the new walmart in your town may save you money for a year or two until they have devastated the local economy and have no incentive to keep prices low. Even if they do, your local area is made worse by the unemployment they cause, and the underemployment they provide. Same thing with Amazon. Are you saving yourself a dollar today to wonder where the retail jobs that helped underpin your community went in a few years? Are you doing all your searches through google when you could maybe do them through Duck Duck Go, or Bing, or just anything that slightly breaks the monopoly that Google has on search?

All of this is stuff that Richard Stallman has been saying for years, and people keep being surprised that he is "correct", but it's usually pretty easy to see that he is just taking a longer term view of things, and understanding that just because an organization acts decently when they are not in a position of power doesn't mean anything about how they will act once they are on top.

In summary, try to think longer term about your decisions, instead of prioritizing immediate convenience, and paltry economic savings, especially when we, as privileged engineers and developers, have the ability and monetary flexibility to do so.