River Scale

[SteelyGlint]

I'm a fairly new mapper (new to these forums, at least), and I've got a few questions about rivers for the experienced mapmakers here.

Mainly, I'm interested in how people draw rivers with shapes similar to the real world. I know that major rivers tend to wind around a lot once they reach a floodplain, but what kind of scale should those meanderings have? How exactly should the shape differ between a major river as it reaches the ocean and a smaller river as it moves from mountainous foothills into the low-lying land? I can recognize when a river looks unnatural (like my first few attempts), but I can't figure out how to make them look realistic.

I started with all of my rivers displayed as the same scale on the map, but that's probably a mistake. I assume I should use wider strokes for the biggest arteries and thinner ones for the tributaries.

I've looked at maps of the kind of rivers I want to imitate: the Seine, the Rhine, the Danube, and the Elbe. Unfortunately, I'm not exactly sure how to replicate their appearance. Do most people just fudge it?

I have access to Illustrator CS2, and a very old copy of Photoshop (way too expensive to buy a new one).