A brick or two of air-drying clay is a great item to get the noggin working on ideas. It comes in white or terra cotta, and you can always work micas or pigments into the clay if you want another color or finish and it is easily found in arts and crafts shops or on-line.I like the terra cotta a lot, and there's no need for a kiln or any baking at all - making it a perfect medium with which to get the kids involved.
It can be rolled out to a 1/4 to 1/2 inch thickness, and cut into simple strips 1", with one end made into an arrow shape, and the names of herbs cut into them to make garden markers.
The clay can be formed into small offering bowls.
I made this wall plaque by fixing a wire loop firmly in the back of the piece while the clay was damp, and then after forming the face (a little angrier than intended, lol...), creating a head dress from dried seedheads, grasses, and flowers. Spices, roots, and herbs could be incorporated, and the gathering of decorative herbs and grasses could be a fun outing with the kids, getting them to look closely at what late autumn still has to offer.
Another idea would be to press cinnamon sticks, star anise, allspice, cloves, etc., into a pleasing pattern on a square or circle of the clay, making certain to make a flat top surface. Be sure to start with a shape that is deep enough to hold the spices and be able to have a flat top, to form a coaster for hot mugs, that will release scent when the heat warms them up.
Since this clay can be painted or decorated in many ways, it could also be used to make pendants. There are TONS of crafts that could be made for gifts. It takes about 24 hours to permanently harden, so you can play for weeks with this one - even waiting until almost the last second!