At the weekend when on a walk how many tree leaves can you identify? You can make your own leaf dial below.
Also a leaf spotter sheet too.
You can also use the Seek inaturalist app https://www.inaturalist.org/pages/seek_app
Also here are some more resources to identify other items in nature.
http://treetoolsforschools.org.uk/activitymenu/?cat=tree_id