You can also try this exercise for your self.
Design an illustration in the style of one of the greats like a classical artist or other. Or what even based on one of your favorite illustrations or illustrators. Then pick a theme and mix them together such as an apple theme and I don't know Leonardo Da Vinci or some illustrator your choose. Then get creative and that's another way you can learn about other styles and take what your like and even add it to your own style. Can even be from comics, animation and more. Its up to you.
Its one of the exercises that was taught to me years ago when I took graphic design classes.

Remember practice first and then find your self.
