Auditors have an unnatural ability to select THE ONE sample you know will get you in trouble...that one sample that caused you heartburn and you were glad to see posted and filed....and that one sample that is almost a year old and you cannot remember the clear details about. Unfortunately, you cannot simply ask your auditors to select a new sample to make your life easier. Once your auditors start asking questions and realize that you can't fully remember why that sample isn't as easy to explain as they would hope, they may conclude that the rest of your samples should be scrutinized even further. So the tip is to write everything down on the journal entry itself, regardless of how ugly it looks! Those notes will keep you sane at the end of your audit period because you'll never remember why you didn't write it all down in the first place!
If this has not happened to you yet, it will at some point because it has happened to all of us at one time or another. My documentation has a lot of handwriting and notations, but I can always answer any question on why I did what I did - and we teach our clients to do that same thing. In the end, this will save you time, money, and most of all the headache!