Cables are a classic feature of many knitting patterns, so it's a good idea to add some cable needles to your knitting kit. These short needles are used to hold stitches so they can easily be moved to where you need them to form your cables. They come in a variety of materials and sizes and can be straight or kinked, depending on preference.
Stitch holders are another knitting kit essential. Used to securely hold live stitches, for example for neckbands or sleeve tops before finishing, they are a tool you'll use again and again.