Before shopping, hand them the list. Bonus: small coins to spend on one thing they pick.
A fruit you've never eaten
Something purple
Bread that's still warm
Honey from somewhere local
A flower bouquet
An herb that smells strong
Cheese you can watch being cut
Something homemade in a jar
A vendor who will let you taste-test
Something with a funny name
The smallest fruit you can buy
The biggest vegetable you can find