Attention Artists! How to draw from imagination?

There's nothing wrong with using references. Using a reference is not the same as copying. If an illustrator draws a picture about things in ancient history, he has to look things up - what some temple looked like or what the average slave used to wear.

Have you noticed that the artists who do fantasy art use references? There's a lot of stuff from the Middle Ages. I'm sure all the artists who paint futuristic spacecrafts don't always make up their own.

Also, copying from photos is one way to practice drawing. You learn about the face and the body that way.

One of the best books on figure drawing is Dynamic Figure Drawing by Hogarth. He also did books on the head and the hands. He shows you very carefully how to "construct" figures, so you don't need models. A good companion for this is Drawing People: How to portray the clothed figure by Bradley.

Drawing human figures well takes a lot of time, so patience is important.

There's a very interesting book that was popular when it came out a long time ago called Drawing on the Right Side of the Brain. The basic idea goes like this. When beginners are copying photographs of people's faces, they do better when the pictures are upside-down! The reason is that when the beginner draws a picture set up the normal way, his mind interferes with what his eyes are seeing. An upside-down picture just gives you shapes and colors that don't mean anything. This is something to remember when you draw things from life or from pictures. From time to time, forget what things are and just think in terms of shapes and colors.