To help with clean up, lay newspaper down on your work area.
Spread peanut butter over the pinecone, getting in all the little crevices. I like to give my kids a plastic knife which makes for easy clean up, too.
Put a cupful of birdseed in a plastic bag (I use a grocery store bag, just make sure there are no holes in it), then place the pinecone inside and gently shake to coat.
Remove the pinecone and tie a piece of string or floral wire around the top stem of the pinecone. It is helpful to wind it around a couple of times to secure it well.
If desired, tie with a pretty ribbon and hang from a tree!