After looking at some exsisting product briefly, i decided to look a certain chair in detail, this is the common utillity chair.
I took many images of this chair from many angles.
From these images i sketched to fully understand the chair.
Then i sketched it out again and added the dimensions so i knew what sort of size chair i would be designing myself. This also gave me the simple anthropermetrics needed to know how high, wide, etc the chair needs to be.