Unless what I'm laying out looks just like a grid, I pretty much always prefer Flexbox. For the majority of cases where I need to do some layout with CSS these

Unless what I'm laying out looks just like a grid, I pretty much always prefer Flexbox. For the majority of cases where I need to do some layout with CSS these days, an image of how to do it via flexbox effortlessly pops into my head. I think that's the key: the majority of layout scenarios can easily be reduced to placing a sliding sequence of items along a string of sorts. Once you understand how that simple model is parameterized (to configure spacing between/around items, how their heights/widths should adapt etc.), I'd say (in my experience anyway) something like 80% of layout scenarios have a simple solution in terms of it, to the point where no thought is even required (though I do still often have to look up parameter names [e.g. align-content vs align-items]! which is kind of annoying).