Building up a custom css is one of my most used techniques but to get there takes a lot of clicks.
Gear > Design > Customize > scroll to the bottom of the long list > Custom css
It’s buried deeper than almost anything else! Is there any way to keep that css editor open all the time? Either by changing the code (probably not feasable) or editing a file in the file system? Would sure save a lot of time!
I’ll add that we specifically built the Theme Styling Tool add-on for adding custom CSS to a site because the custom CSS section is difficult to repeatedly use:
We use this all the time ourselves on sites where a pre-built theme is being used.
This also has live reloading, so you can keep the editor window open, save, and see your CSS updates applied immediately. (video gives a good demo of this)