It's been less than 24 hours: Call the driver — they're usually happy to return your belongings. The call button in your ride history is active for 24 hours after a ride.
More than 24 hours have passed or no agreement reached with driver: Describe your lost item and we'll help you get it back.
I lost the phone I requested the ride with: We'll save you! Write us below and include 1) the number where we can reach you now and 2) the number you requested the ride with.