ooooh newborn nappies! Now just to say Zac was 8lb 13oz so not tiny and he also is quite long so my experience may not be typical. We mostly use shaped nappies on Zac.
We had some nature babies diddy diapers
(nippa fastening) which were great, really cute and trim fitting. Good value too. He outgrew these in rise by 10 weeks old (still loads of waist)
We had some size 0 Easy Peasy Bambeasies
which would not go round him after 2 weeks! I also had a lovely newborn swaddlebees
which would not fit him when he was born even though it was supposed to fit 14lb.
However we have some mediums which fit well from about 8 weeks.
His tots bots
size 1 fit from birth until about 4 months. Sold the bamboozles though - couldn't get a good fit with the applix.
small still fit well and although boring are really reliable.
size 1 fit well from 6 weeks until he outgrew them in the rise at 4 months.
Easy Peasy Bimbles
size 1 fit from about 6 weeks and fit well now.
He wore small motherease rikkis for the first 4 weeks although I would have preferred airflows. From 4 weeks he went into motherease airflow mediums and is still in those now with loads of room.
So we had no need for anything XS and small/ size 0 stuff was outgrown really fast.
Hope that major piece of rambling helped.