My code is usually littered with stuff like print "Foo: ".Dumper(\$foo) if $debug>7;

Often I write those in not knowing if I'll ever want that level of verbosity; usually I never have to crank $debug higher than 2 or 3. (1 just prints progress info usually, depending on what the app is; 2 gives more detail, and so on. 0 only prints actual errors, and undef suppresses non-fatal errors. Anything past 5 is dumping lots of big data structures.) Occasionally I do end up cranking it way up, though, and adding in extra print statements like the above, that I didn't originally anticipate needing.