How do you decide the order of the bridesmaids?

Usually there isnt an order of Bridesmaides per-say, more just a maid of honor and the rest are equal. However if the struggle is to name who is maid of honor, then you can name more than one maid of honor with specific duties listed for each one.

Bridesmaids can be ordered however you like but it is usually done by the closeness of the relationship between them and you or in height. If you do height order with the bridesmaids you should definitely reflect this with the other half of the bridal party so photos look symmetrical.