You mentioned: "many times clients have already done this work. Ask them for copies of their market research reports when you start a project. It will save you a ton of time and effort!" We do this with most of our clients, like you said we have found that around 75% of the have some kind of Market research done, that saves you a lot of time and helps setting up the right SEO Strategy.
If you are using Responsive Web Design, use meta name="viewport" tag to tell the browser how to adjust the content. If you use Dynamic Serving, use the Vary HTTP header to signal your changes depending on the user-agent. If you are using separate URLs, signal the relationship between two URLs by tag with rel="canonical" and rel="alternate" elements.
This post and the Skycraper technique changed my mind about how I approach SEO, I’m not a marketing expert and I haven’t ranked sites that monetize really well, I’m just a guy trying to get some projects moving on and I’m not even in the marketing business so I just wanted to say that the way you write makes the information accesible, even if you’re not a native english speaker as myself.