Often, by mistake, I take over-exposed photos.
In very sunny situations, colours get bleached and one is left with outlines, like a fine water colour.
This can be useful for printing inexpensive photos, as so much less ink is used.
The differences between "over-exposure" and "high-key" are discussed in the link in the title bar.
Somehow, these photos have an other-worldly atmosphere.
I often use them when a small avatar is needed, as the images are less cluttered and stand out well.