Different types of food will attract different types of bird: finches enjoy sunflower and nyger seeds, robins like mealworms, and blackbirds and thrushes love to peck at apples and pears. In cold weather it's best to feed the birds in the morning to replace energy and weight lost overnight. Feeding them again in the late afternoon will keep them going until the following morning – and don't forget to provide fresh water.
Teasel, thistle and other seedheads left in situ will feed flocks of goldfinches, so don't be too hasty to tidy things up at the end of autumn.
In fact, the less tidy you can be, the better – dying plants and leaves are a valuable source of food, warmth and shelter for all sorts of wildlife. Dry, undisturbed vegetation can become a home for toads, and newts will hibernate under piles of logs or stones. Meanwhile, hibernating hedgehogs and slow worms may settle down in an undisturbed compost heap. So be extra careful when turning compost heaps or tidying up around the garden, so that you don't disturb any slumbering animals.