Would agree with all of this. 20th century techniques would cover the 'Gibson Girl' (~1910) which I guess would involve curls, back-combing and use of padding (see the recent film 'Crimson Peak' for inspiration), finger-waving, pin curls and faux-bobs for 1920's - 1930s, victory rolls and snoods for 1940s, setting curls and dressing out for 1950's, back-combing, beehives and a softer curl/flick for 1960's etc. All these styles and techniques can be found in the many books on vintage hair, and youtube.
Pre-20th century, definitely start looking at those old pictures! Braids of different types were also something I understand were popular at various times like Greeks and Romans, Egyptians.
If you happen to be in the UK at some point, you could go to this film studio and do a course there: