Tutorial for bokeh background effects

I just love those lovely backgrounds with the bokeh effect,

Bokeh is defined as the effect of a soft out-of-focus background that you get when shooting a subject, using a fast lens, in photography.

But how can we do it with pencils?
 

Example of a bokeh background, from Suzanne Berry Colouring video.

Suzanne Berry Colouring explains how, with this video tutorial, using Prismacolor pencils.