I believe it's easy to do, but I am missing some details. Somehow, my results are not what I'd wanted them to look like.
- How to draw illustrational lines? (Think of the lines from Windows Vista login screen, for example.)
- … and how to crossfade the created image with another image?
This is what I'm trying to achieve:

Other example of lines I'd like to draw (and later fade over some image):

