1. Competitors Source Code

2. Think Like A Potential Customer

3. Keyword Tools

4. Places

5. Spelling Mistakes

1.) Competitor's Source Code:

Look at your competitor's source code and check their Meta tags. Internet Explorer & Opera: Go to their website and then click “View” on the menu bar and select “Source”. Netscape Navigator & Fire Fox: Click “View” on the menu bar and select “Page Source”. Look at the tag that looks like this : All of the words in quotation and separated by commas are keywords. This method will give you an idea which keywords are profitable for your competitors.

2.) Think Like a Potential Customer:

Try to think of combinations of words that web surfers might search for your product with. If you were selling guitars you might use words like this:

guitar, electric guitar, acoustic guitar, fender stratocaster, fender guitar, affordable guitar, cheap guitar, classic guitar

There are probably hundreds or thousands of combinations you can come up with. Don't forget to use both general keywords like “guitar” and specific keywords like “fender stratocaster”. Usually general keywords will bring you more visitors but specific keywords will convert into sales at a higher rate.

3.) Keyword Tools:

There are great free keyword tools available at YSM (Overture), and Google. Word Tracker is a great keyword tool if you have a little money. You can start an account with them and pay for a day, a week, a month or a year. There is a new keyword tool called Keyword Elite that you can buy. I have never personally used Keyword Elite but a lot of internet marketers are raving about it. These keyword tools will find you hundreds or even thousands of keyword combinations, some of which you wouldn't think of.

4.) Places

For some products or services you might consider using a name of a town, city, state, province, or even the country in the keyword. If you were selling insurance for example you could use this technique provided you actually serviced the area in your keyword phrase.

Example:

florida insurance, insurance florida, ny insurance, insurance ny
us insurance, insurance us, ontario insurance, canadian insurance

5.) Spelling Mistakes:

Hundreds of millions of searches are being performed on the net everyday and nobody is perfect. Spelling mistakes can get you targeted traffic at a fraction of the cost of the normal search term in the pay per click engines. They can also be less competitive as not all marketers are capitalizing on this technique. However, there are a growing number of marketers using this strategy now so it isn't as effective as it used to be.

Example:

gitar, chep guitar, clasic guitar, affordible guitars
gitars, fender strat, gibsin guitar, electic guitar

There are more techniques and tools out there but this should give you a good start and hopefully help you on your way to a successful campaign.