Pole Position Marketing has done a great job with their Keyword Selection Guide, which I highly recommend that you download and read. This article will focus on some of their advice mixed with more knowledge of keyword research and selection.
You won't find tools or tips for beginners here, since I assume you are already familiar with some keyword research techniques. If you're new, explore the SEO Chat keyword research section or do some Google research.
Create a List of Top Level Keywords
Start by identifying "top level" or "core" keywords. Those are one-, two- and three-word long keyword phrases from which many other keywords blossom.
For example, here are the top level keywords for a shop that sells shoes:
Running shoes
Wholesale shoes
High heel shoes
Sandal Shoes
Casual Shoes
Shoes on Sale
In this example the word "shoes" is the absolute core keyword, but it's too competitive and general to spend time on. There is money in it, no doubt, but it will take at least a year to hit the first page on Google, even with a huge investment of time and money.
The search terms above can be combined to produce more keyword phrases. For example, we can consider "wholesale running shoes" or "high heel shoes on sale." At this stage, focus on top level terms and don't worry about anything else.
Dig For More Top Level Terms
Go to your own website and browse through page titles, sections, H tags and links. Identify top level terms. Whenever you spot one, write it down or enter it into a list (using Word, Excel or whatever works for you). Don't record "wholesale running shoes," since the term is already covered with two other top level terms: "running shoes" and "wholesale shoes."
After you've gone through your site, move to your competition. Analyze their page titles, H tags, links and content.
Refrence SEO Chat
