Fantasy art. 
I will share several ideas or concepts that can help you to become more "fluent" in imaginative drawing and painting.  Some of these ideas can be found in examples of "surrealist" artists like Salvador Dali or Rene Magritte.

Fantasy and Imagination Concepts
1. Imagination is the ability to see something that is not really there.
2. Imagination is the ability to place objects in new relationships.
3. Try to imagine spaces that  are solid as "voids" and areas that are voids as solid structure. For example air around an object such as a violin, could be made to look like it is of a solid material of some kind, while the object itself remains an open space.
4. Size. Imagine object which are altered in size. The larger becomes the smaller. The "normal" world is normal to us because of the sizes and proportions which are familiar to us. When you take away this normality fantasy begins. Imagine a group of mountain climbers who are scaling the sides of a piece of cheese.
5. Materials or Substance. Familiar objects have there own special skins, colors, textures or sense of "substance". Imagine various objects exchanging their skins with each other. A pineapple exchanges its skin with a coke bottle, or a wine bottle begins to change into a carrot (Magritte).
 

Assignment
Practice listing materials such as the list below; Each will have a unique surface texture or material substance:
 

Assignment: When you draw or paint, try exchanging materials, qualities or skins with several objects, while keeping the size and outlines somewhat normal. This might be a pretty advanced assignment because beginners do not know how to render realistic looking matter or subtance very well.

Assignment
1. Imagine a great storm. The skies are dark, there are trees blowing in a violent wind, there is a high mountain in the distance. The mountain in opening up in a great earth quake, hot molten lava is pouring through the opening. The earth opens up into a deep chasm. Several people are running to escape.

2. Imagine a human figure slender and dressed in a form fitting leotard. She is fairy-like. She has the wings of a beautiful butterfly. She is dancing gracefully toward us. There is a smooth looking lake, like glass. There are little sparkling lights which appear and disappear all around the view. The trees are white and silver.

3. There is a deep looking harbor at a seaside surrounded by mountain cliffs that go down sharply to the sea. Out of the midst of the seas there are several enormously tall mushrooms. Each grows out of the sea and high into the air. High atop of each mushroom we see lights glowing. It seems that there is a city on top of each mushroom.

4. There are 4 cats standing before us. They are standing on their hind legs. Each cat is wearing a uniform. They are military cats. They are highly decorated and wear sashes covered with metals and golden braid.

5. It is fall. The leaves are fresh and crisp on the ground. There are numerous people who are selecting small and perfectly curved leaves to use as boats on a quiet pond.
The people are much smaller than the leaves. They are taking rides in small groups
toward a castle across the waters.

6. Imagine many bunches of carrots. The carrots are turned so that their pointed
ends are all turned upward. The carrots go on for a great distance.  Here and there
are some figures who are wearing round pointed golden helmets that are just like the carrots in shape. They have suits to match the hats. In the distance there is a castle.
The castle has towers that are shaped like the carrots also.

7. Imagine a room full of babies wearing diapers. They are all working. some push wheel barrows; some carry tool belts or power machines. There is a room with hallways branching out in several directions. There are pipes coming out of the walls, the pipes are steaming. The babies are greasy and sweating.

8. There is a field of prairie dogs. Their habitat is among sandy mounds and burrows. The prairie dogs are in groups. Some are sun bathing, some in lounge chairs drinking cool drinks, others are setting in convertibles trying to make points with some prairie dog chicks.

9. Imagine that you are only 1/2 an inch tall. It is late summer and you are exploring a corn plant. As in the story of Jack and the beanstock you are climbing up the great corn plant and enjoying the scenic views along the way. What do you encounter on the way up?  How are you climbing? What is your favorite place.

 Try to imagine the views which are given to you. Remember these may not be reasonable or rational but that does keep us from being able to visualize them.