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.
Keyword analysis. From nomination, further identify a targeted list of keywords and phrases. Review competitive lists and other pertinent industry sources. Use your preliminary list to determine an indicative number of recent search engine queries and how many websites are competing for each keyword. Prioritize keywords and phrases, plurals, singulars and misspellings. (If search users commonly misspell a keyword, you should identify and use it). Please note that Google will try to correct the term when searching, so use this with care.