[Dilpil]

Taking higher level math classes is a good way to force yourself to maintain good handwriting. You quickly learn that if you want to have any chance of finishing a question, your going to have to write your solution neatly and in easily readable steps.

[teuobk]

...unless you discover the joy of doing your math homework in LaTeX. Beautiful results.

[Zev]

Doesn't quite work for in-class exams where you can't type stuff up.

[SapphireSun]

In high school, I was doing poorly in my freshman math classes partly because I had terrible handwriting and my '6' looked like a 'b'. Try keeping track of your work when you're using the quadratic formula :P

A friendly biology teacher recognized my plight and helped me retrain my handwriting into something legible. It still isn't great, but at least I don't make that mistake anymore.

[rms]

I had to do the same thing in college with t's and +'s, I resisted curling my t's in physics and math class for a while until it was explained to me that everyone did it.

[Xichekolas]

Yeah I started crossing my z's in Calc II because I was getting them mixed up with my 2's.

[mhartl]

I found math classes particularly good for developing my Greek handwriting. (I'm not making this up.)