We decided to be a bit experimental/lazy with the apple tree at the end of the season and just leave some apples on there. The idea being that it would hopefully give the birds something to snack on in the colder months and we wouldnt have to pick and throw away apples that weren't great for doing anything with.
Gotta say its been a big success. So many birds visiting our garden here in the winter months, especially now as the earth is covered in snow. The kids and the cat have become avid winter bird watchers!