Minor nitpick: if you're just preparing a statement, executing it, and throwing the statement handle away, you may be better off just using $dbh->do(...) instead.

And on the subject of your actual point -- I find this sort of "good programming" arises mostly with orthogonal code: each separate chunk of your code does one thing, does it well, does nothing else, and doesn't depend on anything more than it needs to do its job. Writing orthogonal code (modules, subroutines, etc) gives you a good-sized toolbox of code that you can just plug in and use, and (for me, at least) most of these tools come by decomposing a problem into chunks, then generalizing those chunks just a little.