Treasure Chest
How about giving away our greatest treasure, something of infinite value but with a double intention? For the idea we're proposing, we suggest buying one of those wooden chests with a front clasp; the older the chest looks, the more realistic the idea of finding a treasure of incalculable value will be. We think the idea can gain a lot if you prepare it on a beach or somewhere with sand. You can create a map that leads your partner to this precious treasure (the map could be like those in pirate movies, for example, 'Pirates of the Caribbean'). It's worth mentioning that what will add more uniqueness to this idea is the mentioned treasure. To do this, at the bottom of the chest, you'll place a photo of your partner and cover it with a bunch of chocolate coins. To finish, put a note inside the chest lid that says, 'AT THE BOTTOM OF THE CHEST IS THE TRUE TREASURE OF MY LIFE, DISCOVER IT.' When they remove the coins and discover their photo, they'll realize the value they hold in our lives.