I'm looking for guidelines on how to organize a good (IRL) treasure hunt.
Are there steps to follow to ensure the available locations are used to the fullest? Good practices to organize my research ? Methods to write the clues ?
I'm quite lost here and I want to do my best. If possible, I'd prefer a step-by-step guide.
I first wrote a generic question so the answer could be useful to someone else but it ended up being too broad.
The treasure hunt in question is for a group of children composed of eight eleven-ish years old and a few younger ones. I don't think they'll have smartphones, but if one of them do they won't be able to use it since the coverage is terrible here. Most of them know the location relatively well.
The settings is my grandmother's home, a three stories house with a large garden, in a village in the south of France (Aveyron to be precise).
The house is full of old/interesting furniture (grandfather clock, massive 60's TV set, fireplace, bookshelves filled with history or decorative books, a gross stuffed owl, a collection of Murano glass fishes, my uncles and aunts' things from when they were teenagers, wardrobes with mirrors, etc.).
It has an attic, a cellar, two kitchens, two bathrooms, a corridor that used to be a bathroom, six bedrooms, an office, what was a store ten years ago (now a TV room but still has a shop-window overlooking the street and a one-way mirror allowing people in the kitchen to see what's going on inside), a dinning room, a sewing room, a garage, a room used only when killing rabbits and making preserves and my grandfather's workshops (which we won't use since they're full of scrap metal parts and rusty cars).
The garden has a willow tree, chestnut trees, hedges, rabbits cages in a corner, a small stone table and lots of good hiding spots, but not many flowers. There's also a vegetable garden two streets away.
The village itself is not very interesting, there's a church (old and always open), a small market place, a few shops, and that's it.
Most of the clues should be in the house and garden, but since there's not many cars, and the kids are old enough, they can leave the house and search for a couple of clues in the village.
I thought there would be enough materials to organize an interesting treasure hunt for my cousin's birthday (apparently she loves this kind of activity), but I'm afraid the path will be too short or the clues too obvious (something like "Yay! You found the 6th clue, now go to the attic to find the 7th!").
PS : I'm not a fluent English speaker, please tell me if you see grammar mistakes or badly translated expressions.