I don't believe that you trully lived unless you've tasted every season at their full strength, with their own colors and smells. Besides the spring, the autumn is probably the most beautiful of them: the heat of the summer is still present, but it's starting to get colder and the mists of the night can seem somehow magical when you are gathering around the fire with your friends, the colors are changing from the green of the plants and the gold of the sun in the shiny days into the yellow and green and brown of the autumn. There is nothing more beautiful than the hills covered with forests into the autumn, with their entire spectrum of colors and smells... this is probably the most important reason people are trying to get small parts of the forest (things to remind them about that beauty during the winter) into their homes, trying to prolong the moment until the spring.
From this perspective, taking advange of nature as acorns, leaves, twigs, pinecones and other natural occuring itmes is a lot of fun for children (of any age) during this season. The craft ideas are limited only by your imagination and your abilities: you can make almost anything with these natural products.
For example, after the first frost of the automn has touched the follage you can still preserve twigs, leaves, dried weeds and certain flowers transforming them in something new and colorful as paintings and jewerly (such that are precious only for kids). To accomplish this craft you have to take a hike into the woord to your parents or older friends, or go for a a walk along a roadside and collect them. Look for the prettily shaped ones and keep in mind how they would look into a vase or bowl. Make sure that the items what you are collecting are dry. You can get gold, silver or bronze colored paints or jewerly (yes, you can combine the leaves and weed), but the effect will be more marked if you use contrasting colors. The most important thing is to use your imagination and to love the result of your work.
Another craft idea for kids is to create bouquest of dried flowers and/or leaves to decorate the homes or schools. Cat-tails and sun flowers are a very good example.
Using the leaves, acord, twigs, pinecones and flowers you can always make table centerpieses, hats made of leaves or flowers, figures and dolls, log cabin, etc. Having a sign that marks the page you stop reading a book from natural item can be a life-time memory to remind you about your childhood. Another idea to decorate your house is to string up leaves, weeds and pinecones onto a string - hang the string garland from one corner of your room or your porch to another and you will have a great autumn party decoration. As decoration you can always have corn husk autumn dolls, corn husk puppets, ghost leaf.
By the other way, in the autumn there are the harvests. All the fruits and the cereals are harvested, the land is also prepared for the next year's harvest and so on. As activity for kids helping their parents, grandparends and friends from the countryside for these operation can be very educational and helpul in life. Also, they can develop some crafts they have never though about... helping other with their activites or with the products of the autumn harvest. The apples are very good when they are covered with chocolate or honey, there are receipes to prepare sweets based on the autumn apple harvest in combination with different sweet elements from the kitchen.
In some parts of the world apples are also used as support for candlestick or stamp bags.