Google Moving to Google AdWords A Hands-On Guide for Premium Advertisers - Manual (Page 11)

Use keyword targeting. Take advantage of broad match, exact match, phrase
match, and negative keywords.
Use plurals and spelling variations. Common spelling variations, including
misspellings and plurals, can increase the chances your ad will be displayed.
Check your keywords on Google. Perform a Google search on your new list of
keywords, and adjust them based on the results you see. Don’t forget to check your
site logs to see which keywords your customers are using.
Group keywords. Structure them by theme or category into specifi c ad groups. You
might divide your campaign into several targeted groups and one catch-all, or create
groups for lots of individual keywords. Then create ads for each group or keyword.
Get additional help. Your Google account team can help you refi ne or expand
keyword lists, and can also help group keywords and select the best matching
options. Our vertical market experts can provide direction on keywords that perform
well for your industry.
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