A commonly used trick to create better looking hair, if you want to have a better look, is to use multiple hair particle systems. If one uses a single hair particle group it becomes difficult to comb it precisely.
With more particle systems you get better control over them by combing only a part. You be able to comb less hair but with more control, and be more precisely without without affecting wrong hairs.
Those are only 4 hair groups but you might (weight paint) even more hair particle areas, the best Blender hair models you usually see have lots of them.
Adding another tip, to futher improve precision of the "hair artist" :).
It might be helpfull to comb in ortographic view (press 5 on numpad)
So you get real exact positions (Left / right top) to start your combing width. Together with the earlier tip i was able to put a hairgroup trough a needle. Also be sure to have enough segments in your hair.
And a 3th tip, you might as well add a cylinder, select top face press i, inserts the face repeat a few times, then weight paint the inserts for a tail only hair system.
and a 4th tip, since your character doesnt seam to be a realisit person, you might as well consider unrealistic hair; using (optionally softbody) mesh based hair, here's an advanced one with bones :https://www.youtube.com/watch?v=ZHWflWRkYo0
But if you want to go realistic first 2 answers