Okay I have to admit that I became obsessed with the Catwoman since I got the white gel pen from le_Coquet store on Instagram. They sell art tools, and the owner is such a lovely lady, and it was a pleasure dealing with her!
However, the day I have bought those two pens, I had to try it and the easiest way was to sketch a cat woman! Of course I didn't pay attention to the details and the result was not great enough "facewise."
Later on, I have decided to sketch a better version of the cat woman, and I was pretty happy with the final work. I literally took my time on this one!
My point is that you need to take your time and get patience, and do tons of practice in order to come up with a good work!