Just the separated concepts for the Mane 6 in my NG, from this sheet of sketches >>1400745s
 
Fluttershy has anime mom hair whoops
 
Pinkie keeps her hair back out of her eyes (for the most part) now that her workload has more than doubled.
 
Rarity is similar, keeping her hair back to keep it out of the way. Surprisingly, unlike Pinkie, she had to learn the hard way how foals are with long manes, thus getting the idea to keep it back.
 
Twilight now has a lot more hair than she originally intended to have, that has magic surging through it. She’s not sure how Luna and Celestia have kept up with it. So, she keeps it partially tied up, which also gives her a more formal appearance.
 
AJ hasn’t changed much, but keeps her hair braided, as her ‘little bit of flair’.
 
Rainbow Dash chopped a lot of her mane off. Originally it was an accident involved flaming hoops and lemonade, but kept it off when she realized how much easier it made her stunts.