As a wedding officiant I attend many rehearsals and help all those involved in the wedding ceremony become comfortable with the processional, recessional and any mid ceremony participation.  Often when I speak to the parents, they are anticipating that they will sit on the side that their child is standing on.  While traditionally this is standard practice, I often recommend the opposite; that parents consider sitting opposite from their child.  This works out well as the couples I marry face each other, and as such, their parents would be looking at the back of their heads, not their face unless they switched where they sat!  So speak to your officiant, see how they will be positioning the couple and then request a different seating arrangement.  I have had several parents thank-me for this tip!