The first thing you need to do before gauging your ears is have your ears pierced and fully healed. It's important to make sure your ear piercings are completely healed before beginning the gauging process to prevent infection (via Healthline).
When you are ready, you'll need tapers, plugs, and lubricant. Tapers are pointed tools that begin the stretching process. They come in different sizes, most commonly from 3.2 mm to 12 mm. You'll need the lubricant to coat the tapers to help them push more easily through your earlobe hole. Plugs are essentially the "earrings" that will be placed inside the hole to keep the skin stretched. They come in different materials, such as steel and silicone (via Healthline).
When you're ready to begin gauging your ears, you should massage your earlobe to prepare. Make sure you wash your hands and sterilize your earlobe with alcohol. Then, insert the thinner end of the taper into your pierced hole. Make sure to go slowly. When you get the taper inserted, put your plug at the thicker end of the taper and continue moving the taper through, leaving the plug in the piercing. If you feel pain, you may be using tapers that are too big or pushing too hard.
Once your plugs are inserted, you want to make sure you treat your new gauges like a brand new ear piercing, cleaning them twice a day. You should also wait at least six weeks before gauging them again.