Bridesmaids

The modern bride often has attendants of many different ages and dressed in different styles. Once she would not have done so. She would try to make all her maidens look the same as herself to confuse evil spirits. The bridesmaids would even have veils like her to set the demons a puzzle.

It could be trouble just being the bridesmaid  without demons. Some superstitions say that if a young woman is a bridesmaid three times, she won't get to be a bride herself - unless she can manage seven outings.
Similarly, a bridesmaid who stumbled on the way up the aisle was supposed to remain an 'old maid'.

And of course, straining to catch the bride's bouquet so you will wed next could lead to an accident.

There are some other oddities. Apparently in Kentucky:

If a bridesmaid goes to bed backward with her hand over her heart, she will be married before the year is out, provided the first man she sees in the morning is an old one.

Another is all the bridesmaids signing the bottom of the bride's shoe - the one whose name wears most will marry next.

In some places, bridesmaids might sleep with a piece of cake under their pillow and hope to dream of their own groom.

Some modern women might like this one:

If the bride wishes to be the dominant partner in the marriage, she must be the first to buy something after the wedding.  The quickest way to do this was to buy a pin from the chief bridesmaid when changing out of her bridal dress into her travelling outfit.

 Yet still I come back to the idea of evil spirits wanting to ruin the marriage - I find this quite haunting.