3. Finally, there's just good old research through trends and news. Google Trends, keeping up on industry news of the business, and even newsjacking (if there are relevant topics). These all require different resources depending on the business, but once you find the leaders in their news you can not only leverage them for keyword research but also glean insights into how you can become an industry leader yourself (and dominate SEO).
Be sure to re-evaluate these keywords every few months -- once a quarter is a good benchmark, but some businesses like to do it even more often than that. As you gain even more authority in the SERPs, you'll find that you can add more and more keywords to your lists to tackle as you work on maintaining your current presence, and then growing in new areas on top of that.
You can also ask Long Tail Pro to get extra information like “Global Search Volume” (amount of monthly searches globally for each exact-match search term), “Domain Availability” (to see if exact-match domains are available), “Google Title Competition” and “Bing Title Competition” (this is the “allintitle” search that checks the number of sites that are using the same keyword in the title of their pages).
The Search Based Keyword Tool is intended for researching keywords within Google’s Adwords network. Unlike the Keyword Tool, the Search based Keyword Tool is based solely on searches from Google.com. This factor causes the search volumes displayed to be considerably lower than the Keyword Tool. Because this tool is intended for paid search keyword research, it contains additional information on Suggested Bid and Ad/Search Share. The Search Based Keyword Tool is seamlessly integrated into the Google Adwords interface and allows marketers to add keywords to their PPC campaigns without having to login to their Adwords Client Center.
In a nutshell, Long Tail Pro helps you quickly find keywords in bulk based on a seed keyword that you input. In addition to returning hundreds of related keywords, the tool also shows search volume (monthly search volume), advertiser bid, number of words, rank value, and my favorite Keyword Competitiveness (helps you judge the competition and keyword difficulty).