Can I stop pasting in that introduction about what writing exercises are for? We all know by now, yes? Good.

Your neighbour's monologue

Find someone nearby. If there's no one nearby, then think back to someone who caught your eye earlier today, or yesterday. The woman in the hot pink top at the supermarket, the man with the extraordinary nose at the bank. This works best (or perhaps, with least risk of offense and self-censoring) with someone you don't know. Picture in your head (or watch for a moment) what they were doing when you saw them, and their immediate surroundings. It might help to jot these things down at the top of the paper / screen, but it's not essential.

Now, write their stream-of-consciousness. Their inner-monologue, their thoughts running one into the other as they're doing whatever it was they were doing. What were they thinking of? Why are they there, what are they worried about or looking forward to? Keep it up for as long as you can, move them to their next task, location or scenario if possible.