1. Use the Tor Onion Router and/or public computers. 2. Use Pornomode. [1] 3. Understand the communities and functions of websites you're using. 4. Develop an extensive knowledge of Boolean logic for google searching. 5. On the internet, no one knows your a dog: If you must give out personal details while stalking, lie as much as you can.

[1]This is perhaps the funniest item on this list, but it's dead serious. Most contemporary browsers have a "porn" mode where you can turn off all history logging/caching. Safari calls it "private mode," you can call it what you want. It actually won't help obscure your trail, but if you're stalking someone on the internet, it only seems fair that you should act and feel like a guilty teenager while you're doing it.