My favorite milk carton feeder, from tlc.howstuffworks.com:

Plus 5 other simple bird feeders, Reposted from Yahoo voices author Betty Malone:
1. Sunflowers are a natural bird feeder
An easy bird feeder for the fall and early winter months is a completely natural one, sunflowers. If you plant sunflowers next to a wall, fence or building in a sunny spot, and leave them there, the birds will come and peck out the seeds from the sunflower heads. When the weather begins to get cold and you’re cleaning up the sunflower area of the garden, chop off the remaining sunflower heads and let them dry indoors. You can then use the seeds to fill your bird feeders all winter long.
2. Pine Cone bird feeder
As children, we often make the pine cone bird feeder, where you coat a pine cone with peanut butter, then roll it in birdseed and hang it suspended for a tree branch in the yard. It sounds simple and while it won’t last long, it works and you can keep replacing them as all the seed gets eaten. If it rains, however this simple little bird feeder gets ruined, so plan on putting this out when the weather is sunny and dry.
3. Gallon milk jug bird feeder
You can make a simple bird feeder out of a clean plastic milk jug. Just cut a rectangle opening in the side of the milk jug. Poke a few small holes in the bottom of the milk jug to let any accumulated water escape if it rains. Take a sturdy twig from a tree and “poke” a hole underneath the opening to make a perch for birds to stand on and insert the twig in the hole. Make a wire hanger and poke it through the top spout area of the milk jug and suspend from a tree.
And if you want a bird feeder that can be decorated, use a half gallon milk carton, decorate it with markers, cut out designs and glue them on, cut a square opening on opposite sides and then poke a dowel rod section through underneath the feed opening to make a perch for the birds to stand on.
4. Soda Pop Bottle bird feeder
This easy bird feeder, made from a recycled soda pop 2 liter bottle and an aluminum pie plate is durable and yet can be tossed when worn out and replaced with very little cost. Wash the bottle and let it dry. Use a nail or sharp point of the scissors to punchy two holes on either side of the neck of the bottle and run a piece of twine or wire through to form a hanger. Use the scissors to cut out 4 large holes at equal distances around the base of the bottle, about 2 inches wide. . Poke some holes in the bottom of the tin pie plate and then using a heavy duty glue, glue the bottom of the bottle to the inside of the pie plate.
You fill the bird feeder with a funnel and use the opening of the soda pop bottle. As the bird feed settles in the bottle, it works it way slowly out the holes of the bottle, and the birds can perch in the pie plate to eat. Screw the cap back on the bottle until it needs to be refilled with fresh birdseed. Hang your bird feeder from a tree branch or hook along side of house or patio.
5. Homemade wood bird feeder
If you would like to invest in a more sturdy, long lasting bird feeder made out of woods, these plans from the Missouri Department of Conservation are excellent. The bird feeder there is made from wood and plexiglass and can be mounted from a hook or on a pole.
Remember that once you start feeding birds, especially in the winter time, they come to rely on your food. So keep those bird feeders stocked with good quality bird feed. You can buy bird feed in bulk.
Different types of bird feed attracts different birds, so if you’re wanting to attract a specific bird, check out this table with shows which birds like what kind of bird seed.
It’s a wonderful to see a bird feeder with various types of birds clustered around it in the winter; snow on the ground and beautiful birds flocking to your yard to be seen and fed.
by Betty Malone
“There is a land of the living and a land of the dead and the bridge is love, the only survival, the only meaning.” – Thornton Wilder