The easiest way to turn a familiar object into a puppet is to add eyes. Googley eyes or construction paper will do, although there's no limit to the fun ways you can add eyes to an object. Beans, buttons, stickers, get creative!
Once you have eyes, practice finding your puppet's focus. With a preschooler, ask them to help their puppet look at the window, look at the book, look at the door. This focus will give the puppet life. With a smaller child or baby, you can be the puppeteer and make the puppet look at your little one. Have them lock eyes and play peek-a-boo.
Once you have focus, find a distinct way that your puppet moves. Does it bounce? Slither? Stomp?
Finally, add a funny voice. Something that will make your child laugh.
Congrats! You are a puppeteer! If you started with something simple like a sock, move on to a more challenging object like a plate or pot or piano. Remember, ANYTHING can be a puppet!