Household scraps for birds
Feeding garden birds doesn't need to be expensive - many of the things you throw away provide suitable food for birds!
Bacon and other fats
You can put out fat from unsalted cuts of meat in large pieces for the birds. Birds, such as tits, can remove morsels from them. Make sure they are well anchored to prevent large birds flying away with the whole piece! This kind of food can attract magpies and gulls, and also neighbourhood cats. If this is likely to be a problem, it's best avoided.
There is a lot of debate about the suitability of bacon rind, since much of it is salted during the curing process. As long as you can be sure the bacon is not salty, you can put it on your bird table. Since bacon can be too tough for many birds to tackle, chopping it finely will allow a wider variety of birds to eat it.
All types of bread are acceptable to birds, but ideally it should only be just one component in a varied diet. Bread does not contain the necessary protein and fat birds need from their diet, and so it can act as an empty filler. Although bread isn't harmful to birds, try not to offer it in large quantities, since its nutritional value is relatively low. A bird that is on a diet of predominantly, or only bread, can suffer from serious vitamin deficiencies, or starve.
Only put out an amount of bread that birds will eat in a day. Food left on the ground overnight can attract rats. Soaked bread is more easily ingested than stale dry bread, and brown bread is better than white. Crumbled bread is suitable in small quantities, but moisten if it is very dry. During the breeding season, crumble the bread into tiny pieces so that it is only eaten by the adult birds. Dry chunks of bread will choke baby birds, and a chick on a diet of bread may not develop into a healthy fledgling.
Fat, including suet, is particularly welcomed by tits, great spotted woodpeckers, thrushes and wrens. However, please avoid polyunsaturated fats - they don't give the birds the high levels of energy they require in winter.
Mild grated cheese is a favourite with robins, dunnocks, blackbirds and song thrushes. It will also help wrens if you place it under hedgerows and other areas in your garden where you've noticed them feeding.
Baked potatoes (cold and opened up), roast and even mashed potatoes with added real fats are all suitable food for birds. Chips are rarely eaten by birds.
Dried fruits, such as raisins, sultanas and currants are particularly enjoyed by blackbirds, song thrushes and robins. Soak them during spring and summer.
NOTE: as some dogs and cats react badly to these fruits please do not put them out in areas where these animals might get to them.
Apples, pears and other fruit, including bruised and part rotten ones, cut up, are very popular with all thrushes, tits and starlings.
Pastry, cooked or uncooked, is excellent - especially if it has been made with real fats.
Garden birds are practically unable to metabolise salt. It is toxic to them in high quantities and affects their nervous system. Under normal circumstances in the wild, birds are unlikely to take harmful amounts of salt. Never put out salted food onto the bird table, and never add salt to bird baths to keep water ice-free in the winter.