You can use the google adword keyword tool to find the related and popular keywords based on your website.
Today Developer developed same purpose websites but they can not change the keywords of site.So General keyword always used ... So you can resolve such type keyword on page base..........
Research for keyword in not an easy task because all your business or services depend on the ranking on that keyword. So it should be chosen after proper analysis, you can get more ideas from your competitors website.
keyword is the main part of your web site and no one tells his own algorithm how to select it... however, you have to get expereinced in this thing then you have much knowledge about it...... try to use google keyword tool...... but not sure........... it also doesn't give accurate result.
Personally, I use Micro Niche Finder. It's one of the best tools that I have used in a while. Though, I've heard that Market Samurai is a great tool as well but too pricey for my taste.
Google Keyword Search Tool is one of the best way to select keyword for your niche area but make sure to use various combination of tactics, such as you can also make competitor analysis and learn which keyword your competitor are using to optimize their websites. Further make a search with main keyword such as properties in spain and you will get suggestion by Google at the bottom of the page - Make sure to include those keyword in your list as they are keyword which are frequently used by searchers. In this way you can build a Good list of keyword to target.
there's no other free keyword tool better than Google Keyword Tool or you can use Google Wonder Wheel to get some keyword ideas.
Keyword research is ultimately about knowledge. knowledge about your target market, knowledge about your product & knowledge about the problem your customers have. Keyword strategy studio is a powerful software that will help you gain extremely useful keywords insights.