This is the Lean Coffee format variant that we use:
1. Everyone writes a line or two on an index card about what s/he wants to talk about. Write a couple; take only a couple of minutes.
2. Shuffle the cards and create a stack.
3. Pick the first index card from the stack. Start a timer for 5 minutes. Go. People with something to say, do so.
4. When the timer goes off, do thumbs-up/thumbs-horizontal/thumbs-down voting to decide whether to continue or move on to the next index card. Thumbs-up == I want to keep talking about this; thumbs-horizontal == I don’t have anything to say; thumbs-down == I’m done with this topic. If the majority wants to continue, restart the timer for another 3 minutes. Once the majority has nothing more to say, go to the next index card.