Copyright 2019 - M.E. Studios Photography. All rights reserved.
If at all possible have a rehearsal. This forces people in the wedding to learn what they are to do, where they are to stand, how long it will take them to get there and so on. Going through a rehearsal will point out sequencing problems for those in the wedding as well as the photographer / videographer.

Don't rush the rehearsal. Go through it at least three times.

A rehearsal can even be done on the day of the wedding itself. If the wedding is at a rented location, or just not practical to have a rehearsal the night before, do a quick run though before everyone goes off to get dressed.