Using these addi Turbo Circular Needles is a breeze. Just thread your yarn through the needle tip and start knitting as you normally would. The smooth nickel coating helps the yarn glide easily, so you can work on your project faster. When it comes to the non - standard sizing, make sure to double - check the actual size before you start. As for the plastic needle tips of US 36 and US 50, be a bit more careful as they're not as sturdy as metal ones. To keep your needles in good condition, store them in a dry place and avoid bending the cords too much. Clean them gently with a soft cloth if they get dirty. That's all you need to know to get the most out of these amazing knitting needles!