We made this from an old pallet, an empty wine bottle, and thrift store martini glass (plus a little leftover copper wire for hanging). The bottle slides out for easy filling (Decorated Bottle Bird Feeders)
Got any old tires laying around, then take a look at these DIY ideas for recycling those tires rather than taking them to a landfill or tire recycle center. Recycled tires can be steps, swings, chairs and more.
Log Bird Feeder - 23 DIY Birdfeeders That Will Fill Your Garden With Birds (my note: I haven't looked at all of these, but at least one is a terrible idea. The window birdfeeder -- birds could fly into the glass and hurt themselves.