I recently acquired a lightbox, so I have been putting it to good use! This is an example of how I'll be able to use it in the future. I'm actually really excited about this because it means that now I'll be able to do alot of the hard work on cheap paper and the finished product on the bristol without the mess and hassle of all the erasing etc.
Here I have all three pieces laid out so you can see the steps.
Top - Pre-Sketch. This was a class project so I used the blocksheet that we were asked to use. Here I figure out the perspective, work out the placement of the people and shapes etc in pencil.
Center - Pencil Sketch. I lightbox the pre-sketch and work through all the details and shading. I finalize the characters and forms.
Bottom - Ink Final. Here I lightbox sketch a second time, and then ink it. I add textures and line weights and blacks.
I may not use this process every single time, but having the tools and ability to do something like this really helps with the presentation of the final work, and will save alot of cleanup time digitally!