Hi there! (sorry for the late reply)
For the hair, I sculpted the detail and used separate pieces.
What I mean by this is the main body of hair on her scalp is one subtool divided up and sculpted on. The buns are separate parts too, as well as the hair bangs. Buns and Hair bangs are separate polygroup pieces in two big subtools.
To make the main body of hair, I masked out the area for her scalp by painting a mask then used “Extract” found in your subtool pallete.
Give a fair amount of thickness so its no too thin, and so it is just enough to sculpt on top. Make sure that the thickness of your scalp piece is cutting into your character’s hair too, so your hair piece stays grounded to the character’s head. (Eye ball the thickness value since scale and proportion will vary from project to project.)
Use a fair amount of reference for your hair style. Don’t go too overboard, so you can get to work. Make note of how the hair style is made and where your splits are.
Use whichever brushes you’re comfortable with.
I used a combo from Tomas Wittelsbach’s brush pack and SK brush pack coupled with Damian standard and clay brushes. Build up your forms with broader wide brushes to smaller ones. Think of it as a a hierarchy like a pyramid; for instance, you build bigger pieces at the bottom and smaller up top. Furthermore, leave the tiny strands for last.
Be sure to split your areas early to get a sense of where your hair direction is and how its structured.
Hair gets pulled around remember that, so keep tension in mind when making your hair.
I got by using "Lazy mouse" with varying radius values to get those long consistent trails. In addition, sculpt at a low intensity then work your way up. Go from broader to thinner marks, and smooth a little bit over the main body of your locks at low intensity. Keep the transitions sharp to show separation and stacking. Once you have it blocked out, you can keep tweaking and smooth where necessary.
How to get the hair bangs?
I made a very low poly strip of geometry that ran along the hair line (minimal spans) and used “Nanomesh” based on a hair lock mesh from converting one of the hair IMM brushes from SK brush pack. (You can make your own basic mesh for the locks its pretty simple)
Spawn your nanomesh on the geo strip and proceed to tweak your nanomesh settings.
The instances were aligned accordingly with the rotation offsets and y offset. Play with your size, length, and height as well as their Var sliders found next to them. I kept mines uniform but you can play with random distribution and random seed too. You can add multiple instances with varied pieces to better flourish your block up.
After filling up the hair line.
Make your nanomesh instances real and auto group your new meshes. Use move, move topological, elastic, and snake hook to form your hair bangs to the shapes you want them. Add subdivisions to them and sculpt more detail on top just like the scalp.
Hair Buns and final notes
The Hair Buns are just two pieces added on then sculpted over. Although, the spirally pieces over them are just beveled coil meshes with added subdivision and warped with elastic and move brush.
The locks of hair on the sides of her head are styled the same way as the buns and bangs. Separate parts pasted in and tweaked with snake hook and move tools. (try cloth hook too it can give some nice results!)
Fly-aways on the side were were done with curve tube brushes. A handy way to spawn tubes is by creasing an edgeloop on the main hair piece with zmodeler. You create a curve with “Frame Mesh” under Stroke >> Curve Function and have creased edges be the only button turned on. After that select your curve brush and tap on the new curve that was made from earlier. Decide on what you like, delete the curve and proceed to tweak your new hair strand.
I hope this info proved helpful for you 
Don’t hesitate to ask if any part was confusing or lacking.
Enjoy!
Don’t hesitate to ask if any part was confusing or lacking.