As you can see I've flattened my brush a little bit.
I also use small and large diameter of my brush.

Graphics design



Graphics design

That looks better@!

Graphics design

The thinnest hairs I've did with basic 2 or 3 round pixel brush.

Graphics design

Now I would like to do some accessories. I will paint a little bow.

Graphics design



Graphics design



Graphics design



Graphics design



Graphics design

It looks very good
 
with highlights painted in white. Moreover I will add some texture to my bow. As the bow was painted on a separate layer I can fill it with texture using layer styles.

Graphics design

Now the Final step: I will make the apple of eye.

I will just create a new layer, make one dote with basic round brush and use layer styles to give some style to my eye.

Graphics design



Graphics design



Graphics design



Graphics design

So here is basically it. I'm done with my power puff illustration.

I will to some text to balance the composition on the left.

Graphics design



Graphics design



Graphics design