Tweaking the Mac OS system can be tricky if you don't know where to look. For example, customising the Dock with different icons and a new background can involve fiddling with system files and opening the Terminal – not stuff for the faint of heart. There are a number of tweaking utilities out there that are designed to provide a friendlier approach, and one of these is Refinery.
Refinery offers a relatively limited set of customisations compared to rival products like MacPilot, but it does at least provide a vibrant, easy to use interface – once you understand how it works.
The program is split into four sections covering the Dock, Finder, system and application apps. Each section is further split into two tabs: Appearance and Options. As you'd expect, the Appearance tab is where you change various aspects of the section in question – such as changing the login window background or picking a new background image for the Dock. What's not immediately obvious is that you're supposed to provide the alternative images or icons yourself (search the web for plenty of examples), then drag them into place on the Refinery window. A real-time preview shows you what your changes will look like before you apply them.
The Options tab includes a number of tweaks that can be performed, simply by choosing from the options available. These tweaks tend to take effect the moment they're selected, but if you make loads of changes and don't like what you've done there's a handy Restore button ready and waiting to switch everything back to the default settings.
The program is Donationware, so while it's free and fully functional, you will be nagged occasionally to make a donation to help keep Refinery in development.
Competent little tool for customising various aspects of the Mac OS – shame there isn't an easily accessible library of alternative icons and dock backgrounds, though.