If the guy teaching you to be an FI is comfortable enough to put you up for the test, the FIE should be only looking to ratify that decision, not catch you out.
I (and Steve D, if you're listening) were both bricking ourselves the day before - I really didn't think I was ready - but the day dawned, and once we were into it, we were put at ease from the get go. My performance over the day was good enough to get a pass, and so was Steve's.
Pitfalls - not being properly rested (don't burn the candle at both ends), not working hard enough over the course, taking it all too lightly, being unfortunate enough to choose to do the FI course with a below par instructor. Nothing the examiner can do about that.
Tricks ? With a good FIE, there shouldn't be any.