Hi there,
my personal method when using Sections is to create a draft page, design out all of the Sections i would need for my pages, create multiple versions of a section if i need to use it more than once on a page.
Then use the Duplicate Post plugin to create a new Draft each time i want to create a page with Sections. Edit/delete on the new page as necessary.
For global content that may get updated regularly i would use hooks or widgets for this.
This is one are where Gutenberg has got it right with Re-usable blocks so common incontent elements can be updated from one place.