A poppet can be as simple or as elaborate as you like -- it all depends on how much time and effort you want to put into it. You can construct one out of just about any material -- cloth, clay, wood, wax. Use your imagination! In some magical traditions, it's believed that the more work you put into it, and the more complex it is, the stronger your link will be to your goal. Because a poppet is a device for sympathetic magic, all of its components will be symbols of what it is you hope to achieve. You can do your poppet-making as part of the working itself, or it can be made ahead of time so you can use the poppet later on. Which method you choose is really up to you.
Remember, your poppet represents a person, so figure out before you begin who it symbolizes. Is it you? A friend who's asked you for help? An un-named lover you want to bring into your life? A gossip you want to shut up? The possibilities are endless, but just like in any spell working, you'll need to set a goal before you begin. It keeps you from having to deal with "do-overs" later. These instructions are for a basic poppet construction, using fabric. Feel free to modify your design as you need to.