If you’ve read Dan Wellman's introductory series on XUL, you’ll know that there are better uses for your humble text editor than creating stylesheets. The move from Notepad to a dedicated CSS editor will increase your output and give you an advanced environment in which to develop more complicated and effective stylesheets.
Super Styling with a Dedicated CSS Editor - JustStyle and The Morphon (Page 4 of 6 )
JustStyle CSS Editor (free for noncommercial use) is a very well presented application. The working environment is exceptionally clean, and it has that classic Java application look and feel. It is very easy to use; the application window is split into three panes, a tree style viewer listing your styles, a property list and value selector window, and style viewer that shows a breakdown of the selectors and properties of any selected style rules (almost like a preview of how the rule will appear in the end CSS file). There are a wide range of built in selectors, and the application gives you the ability to create your own if necessary.
JustStyle Editing Properties
Possibly the best feature of this program is the ability of the program to insert references to your stylesheet into existing html files, it actually edits the html page itself and adds the necessary link to the stylesheet. This can be done to one html file, or an entire site. The program is offered on a trial basis of 30 days, after which the license states that the program must be registered. The liscence says the program is free for noncommercial use, but the producers site offers no facility to purchase a registration key for those that aren't using it at home. There is not even mention anywhere on the site of how much the program costs. Read into this what you will.
The Morphon CSS Editor (free) is another Java based application, which is pretty obvious from its appearance.
Morphon Adding a Property
Morphon Adding a Selector
It works by building up a stylesheet file from the ground up. You add your selectors and properties as you go along and create the file. It is a compact program and the way it works may seem confusing to some users at first, but if you’re willing to put the time into learning how to use it, it can be a powerful tool in your web design construction kit. It offers full CSS2 and CSS Mobile support, and it seems to be a free application.