Here's some advice from someone who chooses not to do it himself.

1. Start with something about which you are passionate. Notice how "all over the map" my blog is? This is not the way to monetize your blog. Focus on a topic or area about which you have strong opinions, some knowledge, and a real interest in sharing both. Firstly, it will help you blog more frequently (a good monetized blog has at least a post a day, usually more) and secondly it will help shape your agenda (if you are passionate about it, you will have an agenda. If you don't, you probably aren't).
2. Post new content. Make it fresh. Infuse it with your views, your personality, and your agenda. Sharing links is fine. Sharing ideas is profitable. Your ideas and thoughts should be specific. It's not enough to say "I don't like X". Explain why. Convince your audience to not like X as well. Present facts, numbers, anecdotes, and research (preferable original research). Frankly, no one cares that you are a Democrat who hates Republicans or a Republican who hates Democrats or a cat who hats dogs or a guy who hates cancer. They care that you have a reason for your beliefs. They care to hear the reasons more than the beliefs. Let the audience learn who you are through your reasoning, your passion, and your style. You can't do that without posting original content.
3. Socialize. That does not mean allow people to click like or retweet your posts. It means really engage with your audience. Bring them into the conversation. Not just through a good comment system, but through genuine interaction. Feature content from them. Interview or profile them. Engage them with contests and games. Ask their opinion. Make them a community. Do that, and they will return.
4. Find inventive and varies ways to make money. Advertisements are one way. So are partnerships and endorsements. Product placements are another way. The two most difficult to create revenue, though, are donations and subscriptions. You can try them, but are far less likely to see great value. Increase your Youtube views so you can become an affiliate. Join Amazon's affiliate program. Use ads (judiciously) on your site. Find unusual ways

Notice how much of the above I don't do. Also notice what parts I do. I'm not particularly interested in profiting from this blog. I'm not opposed, but I don't seek it out. My old blog was far more profitable, still gets more daily hits even without fresh content, and still generates more money. Oh well. For me, this has always been about experimenting with words and ideas. Sometimes I get lazy and post links to interesting things. Sometimes I post my thoughts. My only hope is that in the end those who read this know the kind of person I am through my content and my writing. For now, that's profit enough.