While adding an trip or updating a trip:

1. Tap the button next to the desired field (ie. destination, purpose, or notes).
   
   
   
2. A list of existing values for that field will display. Now scroll through the list and tap the value you would like to reuse. Then tap the "Ok" button to copy that value to the field
   
   
   
   Reused destination:
   
   
   
3. If you don't find a suitable value tap the "Cancel" button