Using these addi Turbo circular needles is easy. Just thread your yarn through the cord and start knitting as you normally would. The smooth nickel coating helps the yarn slide along effortlessly, so you can work faster. When it comes to the non - standard sizing, make sure to double - check the actual size of the needle you're using to avoid any confusion in your project. As for maintenance, keep the needles clean by wiping them gently with a soft cloth. Avoid using harsh chemicals as they may damage the nickel coating. Store the needles in a dry place and keep them organized to prevent the cords from getting tangled. Have fun knitting with your addi Turbo needles!