I've been beating my head against a wall working on a new suite. The hardest, and most tedious thing has been making the skins resizable. It involves a lot of simple math, and trial and error. Over the course of the next few Workshops I'm going to share some of the things that I've learned about resizing skins, as well as other cool things to do with position formulas and dynamic variables. They'll start off pretty basic and work towards more complicated topics.
I keep seeing taskbar skins that fit only one specific desktop resolution. It's possible to make a skin fit any resolution, and usually it's fairly simple. A decent grasp on simple algebra, geometry and arithmetic helps greatly though. The taskbar below fits any resolution. I'm assuming that you're somewhat familiar with Rainmet