I'd like to note two things. First, you want to watch your width when you're dealing with shapes. Something that tapers and swells smoothly and consistently will look a lot better.
Also, I find when I'm trying to draw smooth curves that I draw them better if I set the curve handles in a way that they flow from one into the next. Let me illustrate with a picture:
The top curve demonstrates uneven width a bit dramatically. But look at the second image; I added dotted lines as imaginary extensions of the curve lines. You see how they gradually intersect? This isn't always possible depending on the shape you're trying to draw, but if you do it you're much more likely to get a curve that looks great. Compare that to some of the more irregular directions that the curves in the first image take.