Hi Cablinius
I like diversity so I have a couple of colours I use for hair. I'd like to think that DE don't like to conform when it comes to hair fashion. For some reason or other though, I do like me some blondes, so I tend to have a lot of them. Maybe my subconscious thinks it is the most decadent haircolor...
Anyway, for highlighting brown hair, I go for a pretty simple, stylised look.
If you look at your first picture for instance, you will see where the light naturally bounces of the topknot. That is where you paint the same pattern as the light makes with a lighter shade of brown than your base. You could use 'Skrag brown' for that probably.
Good luck and i hope to see a project log from you on here someday.