You can generally put a spider web anywhere in your crazy quilt. In the past it was felt that spider webs in a crazy quilt brought good luck. What I like about putting a spider web in my quilt is that spiders and their webs are part of the natural world like the bees and the butterflies and the flowers. I try to include one web in every quilt, maybe even two.
Here is a simple tutorial on how to do a basic web. Here I started with a center space (square) on my block. In this quilt I wanted my web to stand out so I put it in the center. I also decided to use DMC metallic thread. I like the bling metallic thread adds to a piece. If you are a beginner in embroidery you may want to use regular cotton thread and put your work in a hoop. Metallic thread has a tendency to pull on the fabric and can distort it some. To start the web I find the center of the square and come up there. Don't worry about it being in the exact center. Nothing in nature is truly perfect, including spider webs. Next, I extend threads into each of the corners of the square.
On the back of the fabric, I tie off the thread so it will not move and hold it into place. I place my blocks on a pillow while working on them. The pillow raises my work up a little and I can run my hands over my work to be sure everything in lying flat. BE SURE that your threads are lying flat against your block along each step while constructing the web. Next, run thread in between the threads you just placed. Start at the center again and run the thread to the middle edges of block.
And then do this again one more time. These threads will create the spokes of the web. Just like a real spider would do in nature.
Next we will start to add the threads going across the spokes to create the outer design of the web. Again, start towards the center. Not exactly the center, but out just a little bit. When stitching theses, come up on the left side of the spoke, go over spoke, travel with your thread to the next spoke and go down on the right side of the second spoke.
Then come up on the left side and travel to the following spoke. Repeat this until you have gone all the way around. When you come back to your starting point go down on the left side of the spoke. By coming up on the left and down on the right you will lock your spokes into place. This will begin to create the structure of your web. Repeat this with several different level coming out from the center of the web.
Next you want to give the web some detail. This we can do by pulling the across threads up that you just created. To do this bring your needle up slightly above the center of the one of the across threads.
Go under the across thread, go over it, and insert your needle just above where you came up. Almost in the exact same spot you came up. Pull thread tight. This will give your across thread some lift and your web some detail. Do this to all the sections you have created. When you are finished just tie off. If your block has become distorted from the stitching press it with an iron. I had to do that with this block. I covered the block with another piece of fabric as not to burn any of the metallic thread with the heat from the iron.