A simple way I create more intellectual conversations is to be curious. I ask people (even strangers) “What do you love/like/enjoy about your life/work/family/hobby”, then I probe for details “How do you do that?” Why is that so important to you?” I use casual language for asking these questions, so it does not sound contrived. I find that if I am truly interested in the other person, they have a lot to say, that I can learn from.
As a way to bring in the intellectual part…a friend created a card game to help people open to new types and levels of conversation …Conscious Communication. I converted his card set to an online tool for randomly selecting concepts, values and conversation types. I use it to spark new ways of looking at things to have more interesting conversations. I give suggestions on how to use the words. If you use it with a playful attitude, as a game, I think that is where the witty part comes in.
Try asking the next person you have a conversation with “What do you love doing the most?” You may have to ask more than once to show you are really interested. “I mean it…I want to know what you love to do the most?” (the secret is to listen, accept and respect the answer) Have fun!