If you're among those who shy away from drawing, think about it like this: drawing is not copying a subject, rather it is discovering the subject. There is a distinct difference between copying and discovering: to discover is to become aware of something, to find out, to recognize or to discern whereas to copy is to reproduce or emulate, duplicate or replicate.   

If we know we've got to replicate something, we're likely to tense up and feel inadequate, but if our intention is to discover, we're more apt to relax and and be curious.  Curiosity is energizing, but tenseness is wearisome.  The minute we tense up, we restrict our ability, we close out our vigor, we retreat.  

What is drawing anyway?  The broader meaning of to draw is to bring out.  Beyond that, let the linguists and philosophers argue.  Take the word at face value and it becomes about discovering, not duplicating.  

I invite you to give yourself a treat and have a discovery experience with an apple.  

1. Place the apple on a surface at arm's length.  Take a long deep breath.  
2. Close one eye, extend your arm towards the apple with your index finger pointing at it about three inches from its' surface.  
3. Allow your finger to glide around its edges, discovering them.  Move at a rate of about two inches per second or so. Go clockwise over all the edges, then move counter-clockwise over them again.  Continue to move forwards and backwards at least three times, each time, allowing yourself to feel the shape.  Make this a continuous motion, pausing slightly at changes of direction.
4. Open your eye.  Take another long, deep breath.  Note:  I call this process of drawing in the air the Air Glide. 
5. Turn the apple in a different direction and do the Air Glide again.  Try  top up, bottom up, on its side rotated in several different directions.  
6. Take another long, deep breath.
7. Take a bite out of the apple, then do the process again, this time including the new edges you've made with the bite you took.  Once you've gone backward and forwards and turned it in several directions, take another bite and repeat the exercise.  
8. Continue this until you have only the core of the apple left.
9. Take that long, deep breath before and after each Air Glide.

P.S.

The fun of Air Gliding is that you can do it almost anywhere, but the benefit is that you're actually drawing even though there's no evidence left behind.