A simple trick that can help make any chalk line better is to replace the cotton string that comes standard in most chalk boxes with a braided polyester fishing line. There are a couple of reasons to do this.

1 - Chalk does not accumulate on the line and become a big mess.

2 - The polyester line stretches much less you so you get much more accurate chalk lines since they'll snap harder.

The only issue with the polyester line is that it holds less chalk than a cotton line, so you have to rechalk more often. But the lines that you get are so much better that I think it's worth the slight extra effort.