My daughter, when she sits down at the table with blank paper in front of her, pencil in hand, she'll often ask: "mum, what shall I draw?" Knowing the response I would get if I suggested the vase full of flowers, or draw her brother, I offer up other suggestions such as, a fairy holding a suitcase, or a pig as a superhero. These are often much more palatable, but don't necessarily improve her observational skills.
When I was younger I used to wonder what to draw or what to paint too. I didn't want to do the chair in front of me, or the table, or whatever else was in the room with me at the time. Even though I knew that it would be good practice, these things felt boring. And I wanted to feel INSPIRED.
I would often wait until a roll of film had been developed at the chemist (shows how old I am!) and then work from one of the better photos. Either that or I would doodle shapes or people's names, and then decorate them colorfully. Needless to say, this meant that art was not the daily practice it should have been. Nor the observation-filled 10,000 hours.
Things really started to change for me when I got my iPhone with a decent camera. I found I could take a really fast photo of something in passing. It would be in focus, I could frame it on the screen and it come out well exposed. Don't get me wrong, you wouldn't mistake my camera roll for that of Annie leibovitz's, however, it meant that I now no longer had to wonder what I would draw or paint next. I had my own personal catalogue of everything that that had caught my attention, and now it was up to me to use my creativity to make it something other people might also find interesting.
In short, drawing from observation is a great skill to develop, but not at the expense of your motivation. In which case you need to find something that gives you a shot of energy when you think about drawing it. As for my daughter, I'm going to continue to encourage her to draw whatever it is that excites her, and makes her want to pick up a pencil. After all, you can't get better at drawing if you don't ever draw.