I turn on flyspell-mode in my editor.

Update: ... and ignore anything that isn't actually a problem. There are times where lots of items end up being flagged, but that is the cost of spell-checking source code. My "hey, I cannot find this in my spelling rules" indicator is pretty innocuous, so it stays out of the way for most blocks where spelling should be ignored, but is visible enough to catch my eye when I am at least using things that should be spelled properly.