A lot of people are into DIY, do-it-yourself, so it's no surprise that some birdwatchers would want to make their own bird food. Not me, but maybe you. Make Your Own Bird Food by Mark Golley offers a variety of recipes, mostly simple, that can help you entice our feathered friends to feed. The recipes are arranged in broad categories: Seeds and pulses, breads, fruits and vegetables, and suet. Note that the book was originally published in Great Britain so American readers may need to look up some ingredients. Pulses, for example, are seeds that can be cooked, like beans and lentils. Other ingredients, like treacle, may require a trip to a specialty market or a substitution.
Most of the recipes require just mixing ingredients, although a few use pasta and beans that must be cooked (although you can use leftovers from last night's dinner). The introductory information discusses the importance of providing food for birds and each section indicates some of the birds that will be attracted to the meals in that section. Often the birds mentioned are European varieties, like Greenfinches, but the food should be the same as would be fed to other members of the family. I can't say that making your own bird food will always be cheaper but I think it would be a lot of fun, especially for kids.
Golley is a regular contributor to birding magazines and is co-writer for several bird identification guides.