To hold an item for the buyer:

1. Message the buyer and ask them to Like the item or Follow you
2. Deactivate the listing by going to My Page > Selling > Edit > the item > Deactivate
3. You can reactivate the listing at any time for the buyer to purchase
4. Message your buyer on the reactivated listing

Note: Unless you deactivate your listing, it can still be purchased by another user.