Here are some steps that might help: 1. Try to select unique key words that your competitors have not thought of. 2. Optimize for your most profitable key words. How many sales does the key word generate? How much profit is made for each of these sales? 3. Make sure that the key words are very relevant to your site so that people who find your site through your key words will not immediately leave. 4. Try to assemble a list of key words that covers your site very will so that you aren’t leaving anyone or anything out. http://techrelax.com
This is nothing new and has been posted many times here on DP. I've read this from day one after I joined.
My own step to find the right keywords for the site. 1. Try to find more details about the site. If what is the niche/topic of the site. 2. Think as if your the owner and the audience. 3. List a keywords that is related to your site 4. Use keyword suggestion tool to see more synonyms and different variations of your keywords. 5. Find the traffic/number of competitors for each keywords. 6. Pick keywords that is highly search but not too competitive. 7. Then optimized those keywords for your site.