I saw a couple of pictures that illustrate well the concept of complementing your garden structure with the personality of your house/site. First is this one:

You can see how the redwood on the door is repeated in the material of the pergola, but more than that, the rough nature of the rock garden/water feature (can’t tell what it is) matches the simply rough/roughly simple style of the pergola.
Here’s another:

In this case you’ve got a well-tree’d small yard with lots of hardscaping (flagstone paths and patios). The dark-stained, narrow-profile pergolas almost melt into the border of the yard, providing all the things you want a pergola to do, while being very subtle about it. I love this site!
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