Documentation on integrating the LESS module and Omega theme framework.
Usually when creating a sub-theme adding custom stylesheets is as simple as adding a snippet to your theme's .info file:
stylesheets[all] = example.css.less
Only with Omega this goes against the grain and causes the compiled 'example.css.less' to show up before Omega's own CSS files.
So when in Rome, do as Omega does and use the following example:
css[example.css.less][name] = My Project example styles
css[example.css.less][description] = LESS CSS stylesheet for My Project.
css[example.css.less][options][weight] = 10
settings[alpha_css][example.css.less] = 'example.css.less'
When you are building a fresh sub-theme that has yet to be enabled, the above example will work perfectly.
If you tried the above and are wondering why its not working, then the most likely reason is that you already enabled your theme and added the .info entries after, but don't worry there is a simple fix.