Depends on the kind of text to be honest.

Most of the time, if im writing text for paysite tours ill look at the full photo set or movie and use text based on what i see in that, if its marketing text for other sites or products ill see what the site owners did and adjust my text based on their existing text.

The one thing i have found to be a great tool when it comes to writing non-specific marketing text are those late night infomercials you see on TV, i have been paying attention to those for year, they seem to work really well for the companies using them so why not take some of the sales talk they use and use it on your own sites?

Regards,

Lee