Congratulations to Michelle from Charlotte, whose tip won the "Concierge Confidential" contest!
Here's her time-saving tip:
"I use the Reminders app on my iPhone to keep my lists of items to purchase or returns that need to be made. The lists are by store and I have a Reminder alert set to notify me when I arrive at the store using the GPS feature. That way I have a place to keep all those "the next time we are at 'such-and-such' let's be sure to pick up..." This saves me unnecessary trips."
Thanks for the tip, Michelle. And enjoy the book!