At Lark Hill in Salford they have a lot of large mature trees in the grounds. A great job in the autumn is to collect leaves to make leaf mould. This doesn't sound pleasant but the leaves will, after a year or so, rot down to produce a lovely fine compost that is great for adding to your growing areas. It doesn't have a lot of nutrients but it will improve the soil.
We used a lot of large sticks that had fallen from trees or were left over from a woodworking project to construct two leaf bins. We simply pushed larger sticks into the ground and wove willow branches between them.
Children love collecting leaves and it is a nice lesson in reusing what is naturally around us.
If you have large trees, don't install planters or a growing area near them. The tree roots take over, the beds get shaded and covered in leaves and sticks during the autumn and winter.