Synesthesia: How these things are made

I decided to make an illustration about synesthesia, a neurological condition which causes a person to associate sensations with other sensations. For example, a synesthete might see shapes and colors when listening to music. Here is my process for creating the illustration:

The first step, of course, is coffee. Coffee and ideas.

Next, I decide to forgo the sketching stage and instead cover my paper with colorful triangles. (Chaos ensues.)
I squint at the triangles as they dry. More coffee. More ideas.
When things are mostly dry I tape a piece of tracing paper down and draw some lines with a pencil. (I set these lines aside, to be used later.)
Next, I paint a boy with a trumpet. (He also plays the piano, the drums, and the accordion, but he prefers the warm, raspy song of the trumpet.)
Now, let's move to the computer, shall we? I scan the various paintings and pencil lines into my desktop. Then I load everything onto a drive and transfer it to my loyal, albeit slowly dying laptop, because this is where  Our Lord, The Inimitable Photoshop lives. I make the pencil lines white and combine them with the painted triangles. Look:
Now we add our hero and play with the colors and lay it all out on a smooth yellow background. 
And there you have it, friend. Be sure to join us next time.