Take a cue from your venue and the time of day of your wedding to
determine the formality of your dress code. A ball gown might look out
of place on a beach but would be perfect for a hotel ballroom wedding.
Also, keep practicalities in mind when choosing your dress -- for
example, if you’re getting married on an outdoor lawn, skip the train.
Another thing to consider is religious restrictions. If you’re getting
married at a house of worship, check with your ceremony officiant to
find out whether there are any attire guidelines, such as being required
to cover your shoulders.