Honestly, I think the best thing to do is put it on your wish list. Every friend who visits your manor will look at your wish list, and it automatically tells them how many they have of each item on your list. If they want to gift it to you, they will. I have found that most players are very willing to share, especially when they have plenty.
However, if someone does share with you, I think it is important that you thank them by going to their manor and seeing if you have anything on their wish list that you can help them with. If you're just starting out and the other player is a high level player, then they may have much more than you. In that case, you can always leave them tips (if you have any left), leave them a charger (I try to see which ones they need), and leave them a thank you message on their wall. The main thing is to let them know you appreciated their gift.
As you continue to play the game, be sure to give forward. So even if you can't always give back to those who gave you collectibles, when you see someone newer than you, remember the kindness you received and share it with the next new player by giving to them. I have a deal with some of my high level "Santas" that instead of giving back to them, I seek out new players and give to them (I'm pretty new myself). That way the kindness continues to move to the next person.