What I am talking about here is how to not only get good group shots at your wedding, both of the wedding party AND the family shots, but how to get them done quickly so you can get to just enjoying your wedding... like you should! I can't stress this enough. Being prepared for group shots is one of the biggest things you can do as a couple to make your wedding day go smoothly.
1) Make Lists
This comes in two different forms. The first is a list of family/friend groups you want to do at the end of the ceremony. After the list is created, make sure to share it with a trusted family member or better yet, your maid/matron of honor or best man who knows most of the people on the list. The second thing is to compose a list of shot ideas for your wedding party, or better yet, a collection of images (Pinterest works great) that are either an inspiration or in the same style as you'd like. Yes, you can say "I'd really like to try to do this shot." but sometimes there are elements to the shot you like that we won't have (e.g. if we don't have a large European style fountain, it will be hard to shoot a shot of your wedding party standing in one.) Then share that list/board with your photographer so you can discuss the details ahead of time. Don't forget that if your shots require any props those should be on the list(s) too.
2) Dispense the Info
Once you know who will be in your group shots and we've established the ideas you want to pursue with the wedding party, it's time to make sure you get that info to those who need it. In the case of the family/friends group shots, you should send an email to all those who will be in the groups letting them know where they need to be/stay so nobody wanders off. The worst thing that can happen is that a key family member, say mom or day, can't be found and we have to wait for them to do many shots. While that's not the end of the world, it can dampen spirits.
As for the wedding party, you don't necessarily let them all know what's in store for them but if you get your best man/maid/matron of honor on board, they can make sure their respective sides are ready with any props, get to any locations or be ready for poses.
3) Limit "Extra" Photographers
Yes, it's a fact of life that everyone has a phone and many people will have cameras at the wedding but if you can limit the number of people shooting groups when I am, the less likely I'll have people not looking at my camera. If you can print in your program that you wish, if only for this portion of the day's events, that people allow me to take the pictures, that helps. I assure you, I will not elbow grandma out of the way. Most photographers are perfectly able to deal with this situation with grace and without ruffling feathers but it's better not to have to.
4) Don't Worry Much About Awkward Groups
It's a fact of life that there are many blended families, step parents, single divorced parents, etc. 99% of the time, no matter how acrimonious the relationship, families WILL be in pictures together even though they say they don't want to be and it's usually totally fine. That said, it's not weird when they don't. Photographers deal with this situation all the time and it's our job to make sure it's as pleasent as possible for you as a couple AND your families.
5) Scout Your Ceremony Location for Light
While most of the time, your family/friends groups will be done at the same place as your ceremony/arbor was, there are times when the lighting isn't great for that. It's really helpful to talk to your photographer for info (if they've shot there before) or scout your location yourself at the time of the ceremony to see how the light is. Obviously indoor/church weddings aren't much of a concern but if you're doing an outdoor wedding, you want to check for two things; no partial shade/shadows on the area and no harsh, direct light. If you have either of these things, talk to your photographer about the possibility of shooting your groups in a different location, even if it's a few steps away.