I love when couples do not "force" there wedding guests to pick a side during the ceremony, hence bride's side to the left and groom's side to the right. On several occasions I have had a very populated side with only 10-15 guests on the opposite side. That truly makes for awkward photos.
Consider leaving a message at the entrance of the ceremony or inside the wedding program for your guests to "Pick a seat. Not a side". I mean is the purpose of the wedding day to bring two groups of family and friends together in happiness and fellowship.