That sounds like one of the things that I tried. (I realize this is two years later but I was in the hospital most of last year fighting gangrene and other infections. Better now!)
I came across a topic on the Microsoft website. It describes how to create a fill patter where you make a triangular shape in the fill pattern worksheet and then, when it is applied to a lline, it increases the size of the line. This is what I was looking for. However, the ball point pen is the best thing to use to create the original line. Then convert the line over to a regular bezier curve line and then apply the pattern. This will make the line grow over it's length. The neat thing is - the fill pattern can be modified to use curves so you can increase, decrease, and then re-increase the width of the line. This makes it look as if there was a lake or small pond on the river which is really neat. Finally, the fill pattern work area can be increased in size so you have a really long work area. Since only the pattern itself is kept - this makes it so you can have quite a bit of variety on the slowy expanding river. :-)
