Basically, what we need is just cord! Here are some typical cords which used in Chinese Knot making.
#2, diameter = 6.0 mm
#3, diameter = 4.5 mm
#4, diameter = 3.0 mm
#5, diameter = 2.5 mm
#6, diameter = 2.0 mm
#7, diameter = 1.5 mm
#2 and #3 are used for making big decoration, usually use it to decorate your home.
#4 and #5 are the most frequently used, we can use it to make some items which can used for decorating your bag, car, and so on.
#6 and #7 are used for making some small items, like ring, earring, bracelet, etc. or item which can used for decorating your cell phone, key ring, and so on.
What do you need to think about when you buy cord are the diameter of cord and the color. You'd better choose Nylon, but not polyester fiber, because of nylon is brighter.
As a new learner, I suggest that you buy #4 and #5 cord, and red is the most popular color, because it means lucky.
Here are some beautiful items which just knotted by cord.
Here are some useful tools which can help you when you make Chinese Knot.
lighter
pliers
tweezers
needles
colorful pins
measure
hot melt glue gun
some special glue which can work on fabric, plastic, metal, bean, and so on.
These beautiful accessories can help you create more items, of course, these are not necessary.