I am pretty sure i did it all about a month before DD was born, but then we moved anyway 2 days before she was born, so washed a few things in her cupboard again.
I had my bag packed for a while with some of her clothes in there though.

I used and still use the PURITY range of washing liquids for DD, she gets eczema so don't use much perfumed stuff.

HTH.. have fun with it all, no harm in setting up now and washing stuff again closer to the date if bubs hasn't come yet and your worried!