I like to use ‘smart’ quotes (aka typographer’s quotes) but I find default macOS keyboard layout counter-intuitive.

Quote marks come in pairs of left and right. They’re typed using the [ and ] keys.

So I put the left quote marks on the left bracket [, and the right quote marks on the right bracket ].

• To type single quotes, use alt + [ and ].
• To type double quotes, use shift + alt + [ and ].

• Copy British keyboard layout with custom quote marks.bundle to:
  • ~/Library/Keyboard Layouts/ to install it for just your user account
  • /Library/Keyboard Layouts/ to install it for all accounts on your computer
• Open System Preferences ▸ Keyboard ▸ Input sources
• Add British with custom quote marks
• Remove British if you like (sometimes the OS switches back to it randomly)

I made a custom keyboard layout and exported the installer using Ukelele.

If you don’t want to install this, you can still type typographer’s quotes on a default macOS keyboard layout. I just think my shortcuts are nicer.

• To type an left single quote, use alt + ]
• To type a right single quote, use alt + shift + ]
• To type an left double quote, use alt + [
• To type a right double quote, use alt + shift + [