Here are some treasure hunt ideas that you can customize for your date:
The MapThis is a fun way to surprise your date with two gifts; one at the end of the hunt and the hunt itself! Okay, so the basic plan is to be out together and "stumble" across a map or clue that leads to hidden treasure. This map is one you will have hidden earlier, it's just a matter of getting them to find it. For example:
While hiking, take a break near the first clue. If your date doesn't notice it, say "Hey, what's that?" and let them take a look. Inside they'll find a note with an intro like "The Treasure of the Best Guy in Yourtown", along with a clue to the next one. A good type of clue for this one is to write descriptions of things that can be seen from where you're standing, i.e. "Look to the tallest tree, at its base, that's where I'll be", and maybe even insert a riddle or two. Try to keep the clues to no more than 4 or 5 with a total hunt time of 30 minutes or so, that way it's fun without getting tedious.
Head down to the beach and set up your towels where you've buried a bottle containing the first clue. Beaches can be heavily trafficked and you don't want someone to find your bottle, so bury it the night before (or that morning), and mark it with rocks so you can find it easily without others doing so first. Try to set up your date's towel so that they find it themselves, but you can find it for them at any time during the day if you want to have lunch or go swimming first. Light-colored bottles make it easy to see the message inside, and be sure to scrub any labels off. Wine bottles are nice but may be too big, while soda or beer bottles also work and can be corked to seal. Descriptive clues are good for this one too, and if you're worried about someone finding the treasure before your date does, the last clue can always be something like "Give your favorite guy a kiss on the cheek, he may have something for you."
The only setup required is for you to visit the spot ahead of time, using your imagination to plan a fun trail, and hide the clues. Remember to bring along a pen, paper, and maybe some tape, along with small containers or baggies if you think the clues may get wet.
Scavenger huntScavenger hunts are fun in a different way than regular treasure hunts because even though they don't have clues or riddles, it can be more exciting racing against the clock! To start, go somewhere interesting like a good part of the city, a wharf, the beach, a shopping center, or anywhere else with lots of things, and write down all kinds of objects for your list, making it a mix of easy and difficult stuff. Surprise hunts are the best and you can pull it off in a few ways; first, have them meet you in a certain area and when they get there (you're hidden nearby) call or text with instructions on where to find the list. For example, text "Look under the mailbox" or "Ask the manager at Starbucks for an envelope" and "Have fun!" You could also just be out together and when you get to the starting spot, ask them the time, hand them an envelope, and say "Good luck!". The list should have an introduction and rules, such as "Photograph all the items you can within 30 minutes and meet me at the coffee shop. Don't be late, every minute over is -1 point!" It should also tell them what they're playing for, i.e. 1-10 items = a kiss, 10-20 = you take them to any movie they want tonight, 21-30 = they get dessert after the movie, 31-40 = they get a massage after dessert, etc.
It's fun to see your date run around; think about a place where you can sit off to the side and watch the show. If they like riddles, you can work those into the list by including items like oranges as "I'm round, love the letter C, and come from Florida". Whatever variations you use, just make sure they know how to use the camera on their phone or give them one at the start of the hunt.
Scavenger hunts can also be a fun double date. Each couple works up a list of 100 or so items for the other and whichever team photographs the most gets free lunch on the other!
PhotographsThis hunt uses photographs to guide your date from clue to clue until they find the treasure, which is you! Each set of photos should include a distinctive one of the feature they will recognize, like a building, unusual tree, parking lot, or playground, along with a close-up of the area in which the clue is hidden. Take the tree example, you might include a large photo of the tree where you first kissed and then another of a nearby rock or bush where the next set of photos is hidden. You could also give them a written clue or address and then a close-up photo of some physical feature. The last clue will be to a restaurant where you're waiting for lunch, a picnic at the beach, a cafe for coffee and dessert, or even their place where you're waiting with a movie, a massage, or more.
KidnappingFor this idea, something special to your date has been kidnapped and they must meet a list of demands to get it back. The something special can be a pet, favorite hat, stuffed animal, t-shirt, or even you! Start off by making a ransom note out of cut-out magazine or newspaper letters that tells them what's been kidnapped and if they ever want to see it again they'll follow your instructions. Cutting and pasting the letters for the note will take a while so try to keep it brief, but it's a good touch that your date will appreciate (busy people can use this ransom note generator). If they're coming over you could leave the note in an envelope on the front door, or go to their place and put it on their windshield or front door.
The kidnappers have stolen your phone and will only use text messages to direct your date along the trail. The path you choose depends on what you want to do that night; it can be as simple as sending them to buy popcorn and soda for the movie you rented or more risque like candles and massage oil for a full body rubdown. Good items could be berries or grapes, dessert, champagne or wine, candles, massage oil, bubble bath, incense, a flower, a blindfold, or whatever else comes to mind! Part of the fun is giving them hints about what's to come while not making it too obvious, so make them pick up some random items along the way too. When they're buying that bottle of wine, you might as well have them grab a pencil or Chapstick too. Remember to stay in character; reply to their first text with something like "Go to the liquor store on the corner of 1st and 2nd Street. Text when you arrive and wait for instructions". And don't answer their phone calls!
After sending them around to a few spots, lead them to the final location, which can be your place, a hotel room, an outdoor location, or whatever. Have a good time and take it as far as you like. When they finally arrive, you can be blindfolded with a note that says "It takes one good kiss to free me" or maybe you go a little farther and are tied up in bed with candles lit and a note on the door that says "Do whatever you want with the person inside", signed "The Kidnapper".