Packing for Travel

I'm pretty good at packing, I can narrow down my wardrobe to mix and match.  I know how to reduce my cosmetics and toiletries into containers that contain just what a I need and no more.  But unknown weather conditions require a few extra pieces  And then shoes!  I'm sorry, one comfortable pair does not cover all occasions.  And neither do two pair.  And really, who can travel with less than 4 pair.