@Johan Sandstrom -

I believe the gist of Jefro's post is that the theme is a figment of ones imagination, and most often it's your imagination, not the reader. The general rule of thumb is keep it as simple and basic as it needs to be for the type of content you have. Try using a freebie like Suffusion that you can morph into as much, or little, as you need.

And many, in fact a great many of the more trafficked sites are using the default them (which is actually very good). Great content compels people to engage. And an engaged group, even a small one, are more apt to trust you, and more likely to buy from you.