Drawing has everything to do with good observation and that's something everybody has to learn. And after that, you have to experiment and practice.
There are playful exercises I used in my classes, inspired on this book:
Some background information: http://www.learn-to-draw-right.com/right-brain-drawing.html
It's a non-convential approach on drawing.
The exercises are developed to look in a different way, loosening and the childlike joy of drawing. Totally not result-oriented, but playful, draw to draw.
It helped me greatly in developing my own skills, so I can recommend it to everyone!