Shell Collecting

The largest border along traditionally angelic territory lay along the ocean. As such, vast beaches lined one side and for many years, angels believed that new life came from the water. This belief came from the myth of the first angel, who was said to have left the seas and attempted to see the sky. Angels gained wings through a fervent wish to 'swim' among the clouds. 
At one time, angels believed that seashells were the remnants of their ancestors and contained spiritual traces. These could be harnessed for magical working, specifically divination. 
However, as time went on, the nature of the magic was more fully investigated and it was found that components of the shells themselves, rather than any spiritual power, was responsible for their usefulness in magical rituals. Divination itself also fell out of fashion as more practical uses of magic became far more common. 
Angels now consider the collection of shells to be an old fashioned hobby. Some continue to do so simply for the appreciation of shells or for their use in practical magic, but there are a few who still believe in the power of divination and sea bound ancestors. 
To those who believe, particular shells are thought to be more useful in connecting with certain ancestors. Oysters are used for mundane matters, like determining the week's weather, while crab shells are said to be for divining whether a marriage will last greater than ten years. 
The best time to collect shells is at sunrise or sunset, when the water can be seen in many colors. These colors enhance the spiritual properties of the shells with many souls and thus give them more power. 
Seeing a large collection of shells in someone's home signifies to most angels that they are either a marine botanist or deeply mired in old traditions.