After you've determined what size you're at now, you can buy some jewelry in the next size up to start the stretching process! There is a wide range of body jewelry to choose from, but you should only stretch with smooth, non-porous materials. Stick to steel, titanium, glass or pyrex jewelry to use in your fresh stretches. Additionally, you should only use single-flared or non-flared body jewelry to stretch with.

If you've been at your current size for a very long time, it may be safe to pop in your new body jewelry without any additional materials. This is called dead stretching, and is only recommended when your piercings are beyond healed at their current size. In any other case, you should probably use the tapering method to stretch. Buy a taper in the same size as your jewelry -- long, steel tapers are preferred, but any taper is better than none. You only need one taper to stretch multiple piercings, and piercing tapers shouldn't be worn as body jewelry (although some of them are very pretty!).

Something else that can be extremely helpful for stretching is some type of lubricant to help your new body jewelry in. Some types of oils are excellent for this type of application, such as jojoba or emu oil. Any type of water-based lubricant would also be fine. Avoid oil-based lubricants, such as petroleum jelly (Vaseline).