Sometimes, we write ourselves into stale parts of the story, but we need to add length or depth to it still. Among many other things, if you have two characters together, you can indulge in a 20-questions conversation, or have someone get especially inquisitive about what they do on their off time.
While it adds to wordcount, it can also help you flesh out parts of the characters and their personalities, even if it strays somewhat off topic.
Find something related, or not, and jump on it. Are they in the middle of an action scene and can somehow wiggle in a pause? Or are they on a break from work or their typical antics and trying to relax? Maybe they’re reading a book in the middle of a coffee house and are being decidedly reflective about something– interrupt it. Have someone sit down beside them and ask them what they’re reading.
This also works for conversations that need to last but you’re running out of steam with. Find a different direction and run it as long as you can, until you find a way to hook in.
For a more specific prompt , you can start with, “So about that _____.”
– The Novice Wordsmith