Same as Mel, I'm a bit slack with the whole prewashing thing. And with NBs you only get a very short time in the nappy so I think DS's only got the 1 prewash. DDs used to go straight on her.
They say 5 times for bamboo.
I use bicarb (2tbs) on my nappies and 3 drops of essential oil in the rinse (usually lavender or teatree - got that tip from Limeslice).
I'f I'm in a rush I just use a 1/4 scoop of regular powder.