Well, these errors I've found by:
A) Clicking thru the preferences (and every button and menu, and other dialogs) and looking at the texts. You spot it right away if sentences are too long because you see only half of the text at the end.
And for other sentences/labels where you don't see anything wrong at first sight, you can get a hint that the text is too long if they don't contain a ":" at the end. The same for other normal sentences when they don't contain a "." at the end...
B) Useing Choli's translator for a check for forgotten/misspelled topics and keys. (I can't stress enough on how important that application is for translators
)
C) And for some errors I look specificly, like OriginalFormat, CurrentLanguageA, Def1Cmd, EnableCheck, etc...
Actually writing the "report" takes 10 times longer then checking for all those things...