That's similar to how I structure mine, however, I find that using sub-headings is the best way to do it, so I use this structure:
/*********************
* GLOBAL *
*********************/
/* All of the common stuff goes here under the appropriate sub headings */
/* Heading formatting */
/* Text formatting */
/* Form formatting */
/* Table formatting */
/* etc */
/*********************
* LAYOUT *
*********************/
/* All the layout things go here under sub-headings */
/* Header */
/* Left Sidebar */
/* Right Sidebar */
/* Footer */
/*********************
* NAVIGATION *
*********************/
/* I put navigation separate to the layout as there can be a number of navigation points under their sub-headings */
/* Main (horizontal) Navigation */
/* Left Navigation */
/* Right Navigation */
/* Breadcrumb Navigation */
/*********************
* FORMS *
*********************/
/* Any form formatting that varies from the common formatting, if there are multiple differently formatted forms, then use sub-headings */
/*********************
* TABLES *
*********************/
/* Same deal as forms */
/*********************
* LISTS *
*********************/
/* Same deal as forms and tables */
/*********************
* CONTENT *
*********************/
/* Any specific formatting for particular pages, grouped by sub-headings for the page the same way as forms, tables and lists */
/*********************
* CSS SUPPORT *
*********************/
/* This is for any special formatting that can be applied to any element on any page and have it override the regular formatting for that item. For example, this might have things like: */
.float-right { float: right; }
.float-left { float: left; }
.float-center { margin-left: auto; margin-right: auto; }
.clear { clear: both }
.clear-block { display: block }
.text-left { text-align: left }
.text-right { text-align: right }
.text-center { text-align: center }
.text-justify { text-align: justify }
.bold { font-weight: bold }
.italic { font-style: italic }
.underline { border-bottom: 1px solid }
.nopadding { padding: 0 }
.nobullet { list-style: none; list-style-image: none }
/* etc */
Hope that helps.
I generally don't recommend writing on a single line like that though, or like suggested in the link Adam posted, they get very difficult to skim over if they get long. For the examples above, it was just quicker to type them that way so I didn't have to indent every line.
For formatting I would recommend this structure:
.class {
width: 200px;
height: 200px;
border: 1px solid #000000;
}
And so on, I put the structure of the class or ID at the top, then any other formatting, like the font etc below that. Makes it very quick and clear to skim over.