In this tutorial I will show you how to implement the power of LESS in Drupal using Omega theme. You can check out the these links if you want to know more about LESS and DRY because I am not going to talk about these things in this tutorial.
Once done, things are not complete, you need to add the php library for LESS which you can download from here: http://leafo.net/lessphp/
Once that is done, it's time to add the .less file in the info file of our theme.
Omega subtheme info file
This is very important because if you don't do this and instead use the code given in the install file, your CSS file will come before the Omega theme CSS files and so the styles in the LESS files will not effect. Believe me this one took me a lot of time to get. But thanks to this link I finally managed to get this.
Once this is done; cache cleared; you can go to the theme settings page and see that the LESS file is now available to be included. Here is the screenshot:
Settings page for the Omega Subtheme Styles
And when you have this thing in place, you are ready to go...