For this exercise, I was asked to draw out a grid on an A3 piece of paper. The grid will show 8 panels. I have taken photos showing my process below.
First, I measured the length and width of the A3 page and divided it by 2 so that I could find the center of the page. I then turned my page around and found the center again. I then divided the page by 4 so that I could create the 4 panels. Then did the same on the other side so that I had 8 panels.
I then added a line so that the area between all my panels had a 1cm space between them.
Finally, I used a fine liner pen in size 0.8 to outline the panels.
I have now created an 8-panel grid.