I started the fillings with Trolley Net (p.61) and it went easier than I expected. After I turned my second corner, I thought I would change to a different filling. That was harder than I expected, I couldn't do it without making an ugly gaping hole. After lacing back 3 times, I decided to stop the fight and continue with Trolley Net.
I have contained my working bobbins in my worker cloth and pinned it down to my pillow. This lets me work on my fillings with no distractions.
The green pin is in place to remind me where I ended off. I forgot to remove it for the picture.