I am experimenting with the masking tool in Manga.
This allows each section to be decorated and played with, without risking overlap and ruining another section. Basically, it means you can't colour over the line!!
Another tool I am enjoying is the symmetry rulers. The 12 point symmetry ruler is just fun!! Reminds me of the spyrograph fun from the early days. Even the teens have had a bit of fun with this. Looks really good with a mix of colours.