I will collect some useful tutorials here. Either about sewing or about style.

General Sewing Tutorials 
Sewaholic's sewtionary - a whole lot of advice how to do stuff
Zip fly tutorial

Specific Sewing Tutorials
Picnic blanket skirt by Tilly
Bow belt by Tilly
Jenny belt by Lladybird

Vintage hairstyle

Vintage make-up
Glamour Daze - Vintage fashion and beauty archive, well organized make-up tutorials

Wardrobe style
Frenc Chic - how to achieve the French chic style
How to look older: wardrobe - tips on how to look more mature