From Scott Berku’s page:
You can sit or lay down. Once you are in position, close your eyes and relax. Just sit there for a minute and think about anything you want. After about a minute, start thinking about the neighborhood or subdivision in which your home is located. In your mind see your neighbors houses, the roads, the streets, the trees. After you can see your neighborhood clearly, move down the road your house is on and see the houses along the way…
When you begin, you will only be able to concentrate for a few seconds or minutes. If you work at it every day, though, you can build your concentration just as you can build the strength in your arms
I, Geek 