Lifestyle photo sessions can seem a bit... vague.
What do I wear? What do I bring? Is there a schedule to this?
First up, create your own goals for the day. Somewhere along the way, it was decided to bring a photographer out to document [fill in the blank]. What you're hoping to get out of the session, communicated with everyone involved, will answer all other questions.
Most people looking for Lifestyle Photography would agree with this:
"I'm looking for natural photos of our family interacting in a way that you forget a photographer is present."
If this is you then...
1. I'd suggest no matchy-match clothing. But do wear clothes that flatter and are well-kept. A cohesive look with a family works well too (aka all bright colors or all neutrals).
2. Bring items that play up personalities. Stuffed animals for little ones, an umbrella for rainy days, cocktails for the happy adults, etc.
3. And there is no schedule but some thought-out activity is ideal. Playing a game together, cooking a meal, taking a walk.
All of these suggestions create natural interaction and bring out a great side for portraits.
Your session is unique though, chat with your photographer about what details should be highlighted in your lifestyle session.