The school year is in full swing. Perhaps like many parents, your afternoons and evenings are busy getting kids to sports, music lessons, dance practices, etc. We want to reconnect with our kids and start with "How was your day?". Sometimes the answer is a simple 'fine'. But that isn't much of a conversation.
When my kids were younger, and more willing to share all, we would discuss the 3 worst and 3 best parts about their day. That helped us have a dialogue, and that might be helpful for you. If your kids are a little more tight-lipped, you might like some options in a blog post which has some excellent conversation starters for talking with kids of all ages. There is a set of questions for elementary age students, and another for teens.
I think with a few tweaks you might get some ideas for talking with important adults in your life, as well.