The easiest instruction to give and the hardest instruction to reproduce is... "People are all made up of angles all you have to do is get the angles right"!!!!
The best way to start is from life, and start small, if you give yourself too big a object then when you do not get it right you will disappoint yourself.
People do not always like still life but that is a good place to start, as I was always told the human body is the hardest image to re-create.
Start with a piece of fruit; draw it, paint it, mix media it, get to know the angles and their relationship with each other.
