You can be a cartoonist using a Ball Pen.

Not so professional, but using just a paper, a ball pen and a little photoshop trick will turn yourself into a cartoonist. Below, you will see a few sketches I drew with a ball pen on a paper, then I took those pictures with my phone's camera.

After opening the picture in photoshop, press Ctrl+L or open Image > Adjustments > Levels and the Photoshop Levels Tool Dialogue box will be shown. At the Input Level pane, adjust the sliders which map the black point and white point in order to correct the tonal range and color balance something like below.

Here is the final image after adjusting the trimmed characters into proper positions. Put some dialogue boxes and that's it. Bravo!!! :)

Here is another picture I posted on my blog post here and also on my facebook profile at www.facebook.com/aungmyolinn.

Before

After

For more detail about using Photoshop Levels Tool, see the official Adobe page here.