Having the idea of designing an icon set, I came up with various groups in mind.
I started sketching on paper to visualize them, and consequently digitized them using Adobe Illustrator.
I drew a set of famous musicians, famous bridges, different types of arts, and some of the famous characters Johnny Deep has played in movies.
As can be seen, I went for the characters of Johnny Deep. He is my favorite actor, and I know each of these characters so well, therefore, it was easier for me to get excited with the design with full of ideas in mind.
I went from paper to creating a circle, some main features for the face, and other outlines of its accessories for each character.
Next, I added some gradient colors, and some their names underneath them.
What makes up an icon set is the cohesiveness of its elements, and in this case, it was clearly accomplished by the the unification of gradient colors in each element. Also, the simplicity of each characters by the circular shaped face each one has, the main features used to represent each of them, and their absence of their mouths.
By designing this, I realized how important is to go for something that you like at first, with basic shapes when sketching, especially when you are stuck. You would be surprised by how ideas of other elements would come along.