Just the standard settings. You don't need any other levels than that.
When drawing fibs either way, the 50.0 retracement is very strong and considered the end of the line for a retracement, so If price actually breaks through the 50.0 during a retracement and continues on, it's safe to say that it'll continue in that direction from then on and is no longer in retracement and a new trend has formed.
I trade off the 61.8 (38.2 when drawn the other way) & 50.0 areas when waiting for entries. Bear in mind, I draw my fibs the "other" way around to show the Fibonacci extension levels.
This is a how-to I wrote on how to do that here.
And if you're looking for the best auto Fibonacci drawing tool I personally recommend Mladen's one as it draws the fibs the correct way (in reverse) which was optimized by Mrtools here.
