Slightly related, but mainly a formatting issue, I format my css files as such:

  .foo    { x: y; a: b }
  .bar    { m: n }
  .baz    { background: blah blah url(xyz.png) top left;
            x: y; i: j; }

instead of the more commonly seen:

  .foo {
    x: y;
    a: b;
  }

  .bar {
    m: n
  }

  .baz { 
    background: blah blah url(xyz.png) top left;
    x: y; 
    i: j; 
  }

My format takes up less vertical space in the editor. Sometimes, I can get my entire CSS file into a single page on the screen, reducing the amount of time I spend scrolling and searching. I do split lines when they go off the edge of the space, as seen in the .baz example.