Hi, thanks for the write-up :) The above-mentioned methods are really great in the long run!
But there's one more method(even I am relatively new to it, so please correct me if I get it wrong), which is relatively new and many people don't know about it, and that's Web Monetization. Basically, it is just that people can stream micropayments to your site if they like your content.
Also, even if they don't do it themselves, you get a certain share depending on how much time a person spends on your blog. On average, it's $0.36 per user per hour(I read it somewhere, but I can't recall now).
And yeah, this is a good source too, as all the above methods, though proven to work in the long run, are difficult to get stable at. As they need months of hard work to ascertain factors like ranking, SEO, etc.
This source will prove to kick-start getting some income(although not much, still it gives enough adrenaline rush to keep one motivated) and give new bloggers some hope to continue their work.
Some articles that may help you dive further into the topic: