A useful strategy:

  • Pick two words which you think may produce few Google results and search for them.
  • Examine the summaries of the webpages Google has found for you for any words you would not usually associate with either of your initial search terms.
  • Replace one of your search terms with any such words.
  • Repeat the process if necessary
Example:
  • Initial search: Volcanology Bagpipe
  • One of the summaries contains the very odd word "toadpipe".
  • New search: Volcanology Toadpipe
  • It's a Googlewhack!
Tip: Try using one common and one stupid/esoteric word in your initial search to get the highest scores possible.