I suppose it depends on the specific project or feature. Usually I go for the approach you describe. But more than once I got bitten by doing this for a featur

I suppose it depends on the specific project or feature. Usually I go for the approach you describe. But more than once I got bitten by doing this for a feature or project where things were still very much in flux, and/or in a prototyping phase. In those cases, starting with 'NoSQL' (JSONB columns in Postgres though) would've saved me a lot of trouble, and it would have been much easier, relatively speaking, to migrate my data into proper tables once things solidified. Still, I do find that going for 'SQL' by default has usually been the better choice.