What is the best way to learn how to draw?
Simple answer, practice!
Longer answer: There are three steps that you need to go through in order to draw well. Number 1 is observation, number 2 is understanding and number 3 is application.
Observation – 80%+ of drawing well is observation. Learning to see the world around you with an artists eye. Dont look at a tree and say, I will draw that, then fail. Instead look at the tree in the context of the lanscape it is sitting in. Look at how the branches spread out from the center. See how many times the branches divide into smaller branches, is there a pattern? Squint your eyes and trry to decern – if you had to draw this tree using just 10 lines, which elements would you decide to show? Try to observe the angles of the branches in relation to the horizon, in relation to the trunk, in relation to each other. Does this tree lean to one side, was it wind-swept as a sappling? Or did a deer nibble the young shoots, leading to a deformity? I think you get the idea. Looking and seeing are two different things. To become an artist, regardless of medium you have to learn to observe.
Understanding – If you tried to draw a face and realised it was looking flat or disproportioned. Or you drew a mouth and it looked like an almond instead of some juicy lips. Then, it is likely you do not understand what you are drawing. Try to understand the fundamentals of form. Learn that the mouth actually sits upon a barrel like structure of bone and muscle. Learn that the mouth is controlled by dozens of muscles. Learn that the bottom lip is generally thicker and more succulent than the top lip. Learn that a smile can change the whole shape of the mouth. The same applies to any object whether man made or natural. form follows function, try to understand what the function is and why the forms are the way they are. Then… you can draw a framework in order to add your sketch to.
Application – Efficiency comes through practical application of knowledge, practical application comes from practice. The first time you draw a rabbit, it will suck! The second time it will look slightly better. By the 50th time, it will look so much better. Practice is key. But be sure you are practicing the right things. Dont spend six weeks drawing a box, instead draw a page or two of boxes, then find something that has an underlying form of a box, then draw that object. Later go back and draw some more boxes. The idea, is that you need to learn and practice many different aspect of drawing in order to well… draw well! But unless you apply that knowledge and learn from that experience you will not progress as fast as you possibly could.
I hope this answer helps? Kind Regards, Robin.