Yes, I think this is a great, fundamental question of WordPress editing and content creation by low-level users who are met with the big blank editing area and don’t know how to wrangle html. There are myriad answers: hardcore coding, softcore coding, plugins and everything in-between.
The answer for me is Advanced Custom Fields. I know I’ll be shouted down here since you aren’t meant to answer questions with a plugin solution (yes, that’s totally odd – who has ever used WordPress without a plugin? It even comes shipped with two – one useful and one stupid). Anyway, as far as I’m concerned ACF is core WordPress.
Jump on board and enjoy WordPress at the next level. For you and for your clients.