Recommended boilerplate for building an Envato theme

I’m planning to build my first WordPress theme for Envato. I read the WordPress Theme Coding Requirements which states that themes must use prefixing, be translation ready, and have proper validation/sanitation. Envato also recommends using the Customzier API which I plan to do.

I’m hoping to get some advice from authors. Which open source boilerplate (like Underscores for example) do you recommend as a starting point? Have you used any boilerplate on your themes?

Underscores is the most perfect starter theme you may start with it to create simple blog theme and step by step add more details to your theme until you get there