I spoke about the ACF way of going about building custom blocks for the Gutenberg editor at WordCamp Kansas City today. You can view my slides (with more text added than the presentation version) by clicking here.
Again, some resources to check out:
The ACF Blog is a great resource as they have posts like: Building a Custom Slider Block in 30 minutes with ACF
ACF Blocks – library of precreated ACF blocks
Learning more about developing for Gutenberg (non-ACF-based approach):