It is really hard trying to explain in diagrams, but it's pretty easy to explain in numbers. So first is the seed (zero), then the line (one) Then the two circles (vesica pisces), the four and finally the eight. You can see this system in I-Ching aswell.
Let's look at the making of a human. First you have the head (zero), then the spine (one), the brain (two), shoulders and legs (four) and lastly elbows/hands and knees/feet. Now the cell division during pregnancy. First the female seed (zero), then the male sperm (one) the seed divides (two, four, eight).
Next the hand joints. First the arm (zero). Under your thumb there is is a joint which you use while shaking hands or gripping something (one), then your two thumb joints, your four fingers/joints and the eight joints in these four fingers.
Let's look at the flower of life. It is shaped like a snowflake. You have one center, up and down (two) and the four directions. Eight creates a cube or the four dimensions of reality.
You can see this in trees and other stuff. You just need to look for it!