The sight of TurkeyOnAStick waving his fist in the air as I come away from him kept haunting me, not giving me a single moment of relief. Thus, Here's a brief explanation on how I make my lines.
First, I import my scan to CorelDRAW and, basically, I start tracing over it. I lock the sketch and get to work.
1) As you can see (No, you can't 'cause the icon doesn't show in the caption. WTF?!), I use the pen tool to make a 2-side polygon (It may look like a simple line... but it's not!).
2) In order to twist the lines, I must right-click the on the line and change it to "curve".
3) Here I'm just clicking and holding the mouse button and dragging the curve to make it look as I want to (More or less).
4) A little run-of-the-mill trick: Now I create two nodes and change'em to Asymmetrical.
"What's this doing in the "Anime" Thread?", I'm hearing? Just wait a bit more...