Most of the time children are oblivious to any seriousness involved in a wedding day. Just let them do their thing and they will more than likely provide you with comedy gold. They will yawn in the ceremony, pick their noses during the speeches and dance like there is no tomorrow. If the children belong to the couple getting married all the more reason to photograph them. The couple will love these types of shots. Plus they are great blackmail tools for the parents to use when they are older.
I try and avoid having to add light or dodge in LR when possible. If I'm doing many shots of a group as you mentioned you can't always copy and paste the settings from one to all of them as the heads aren't in exactly the same spots. So you end up having to dodge on every single image and causing yourself a lot more work in post production. That's why if my faces are dark I add a flash (bounced into an umbrella or bounced off a big reflector) off to one side to add light into their eyes. Of the images in the article, NONE of the faces have been dodged.
There are a few bonuses to using accessories well (as well as layers). One is that changing them up a bit throughout the session can give you multiple looks without having to do many wardrobe changes. They can also be something that the subjects can interact with. A sassy little tip of the hat, holding the ends of a scarf while running and letting it billow behind you, grabbing the lapels of a husbands jacket while pulling him close for a kiss – all these little gestures and ways to interact (and become more comfortable in front of the camera) can be made possible with styling choices. Many of my sessions will feature items used outside their intended use or subject. My girls are often seen in mommy’s hats or scarves (scarves can be used in different ways like wrapped around their shoulders, as a hair piece, etc) and they love to wear my costume jewelry.