Struggling with Procreate brushes for watercolor children's book illustrations.

[EthanL]

I'm a traditional illustrator who just switched to using Procreate on an iPad, and I'm overwhelmed by the sheer number of brushes and settings. I'm trying to create children's book illustrations with a textured, watercolor-like feel, but my digital paintings look flat and synthetic. What are the best practices for building a cohesive brush set in Procreate for this style? Should I focus on modifying the default brushes, purchasing custom packs, or creating my own from scratch? Also, how do you effectively use layers and blending modes to build up color and texture without the artwork becoming a muddy mess?