This project is easy and inexpensive, and certainly one the kids can help with. We took a frame from a thrift store, wrapped the inside with string and cotton to make it look like a spider web. Spiders and a "welcome" message were then hung within the network.
Paint the frame black and let it dry.
On the back of the frame, along the edge, hammer in small wire nails. Insert the nails so that it only protrudes about 1/4" from the frame.
Place felt pads on the back of the frame along the corners so the nails don't scratch the house or door.
Wrap the yarn around the wires going back and forth through the frame in a random pattern. Periodically tie the thread.
Behind the thread, spread some of the white cotton material along the same nails.
Place the letters in a random pattern on the thread, close enough so that you can read the word "welcome." We use store-bought self-adhesive lettering, but you can print your own message on sticky paper.
Place the spiders along the front and tuck them into the thread and mesh.