Finishing Touches Edit
This tutorial covers general concepts and structure for creating basic blocks.
The block editor provides a components package which contains numerous prebuilt components you can use to build your block.
You can visually browse the components and what their implementation looks like using the Storybook tool published at https://wordpress.github.io/gutenberg.
The RichText component allows for creating a richer input besides plain text, allowing for bold, italic, links, and other inline formatting. See the RichText Reference for documentation using this component.
The InspectorPanel (the settings on the right for a block) and Block Controls (toolbar controls) have a standard way to be implemented. See the Block controls tutorial for additional information.
The Sidebar tutorial is a good resource on how to create a sidebar for your plugin.
Nested blocks, a block that contains additional blocks, is a common pattern used by various blocks such as Columns, Cover, and Social Links. The InnerBlocks component enables this functionality, see the Using InnerBlocks documentation.
How did they do that
One of the best sources for information and reference is the Block Editor itself, all the core blocks are built the same way. A good way to learn how things are done is to find a core block code that does something close to what you are interested in and then using the same approach for your own block.
All core blocks source are in the block library package on GitHub.
Next Section: Share your Block with the World