Today I thought I'd dissect the above image (the header of my - hopefully - funny site http://www.alien-jobs.com/ ). Hopefully you'll find it interesting, and perhaps even learn a bit about Photoshop.
I don't remember the exact steps it took to arrive at this setup, but in any case, at the bottom there is a layer which looks like the above (it's actually two due to the process through which I ended up with this image, but it could be done with one layer). It might seem like a plain blue box, and that's the base, but at the edges there's a 1px stroke with a special gradient (you might have to look at the larger version to see it). You'll see later that it's made to fit the strokes around the menu bar while at the same time fitting with the tone of the rest of the header.
The city is in overlay mode to fit in with the background color while still letting both light and dark values affect the end result. If you're interesting in knowing how I did it please leave a comment, but in short it's a simple Blender scene + some very basic Photoshop created planets in the background.
Here the menu bar background is added. It's just a shape layer with a solid color and a Gradient Overlay layer style to add some simple depth.
Here's another subtle addition: two lines 2px wide, with a Gradient Overlay layer style that's adding the high-light in the center. The lines consist of two colors: one that's a brighter shade of the main color of the menu bar background, and the other is almost black. The almost black line is topmost on the top line and at the bottom of the bottom line. These small lines add some nice dimensionality, and now you can see where the gradient from the top image fits in the big picture.
And now for the finishing touches: the type. The website name + slogan is in the font Andika Basic (can be downloaded for free from http://scripts.sil.org/andika ). The slogan has a simple Drop Shadow layer style. And the website name has got a slightly more complicated layer style. Easiest to see is the huge Outer Glow in Linear Dodge blend mode, but there's also a slight Drop Shadow and a 1px Stroke which together adds some dimensionality to the text. If you want to take a closer look at the later layer style feel free to download it: http://feneur.com/fdad/Alien_Jobs_Blue.asl
To install it go to Edit-->Preset Manager, then choose Styles from the drop-down list. After that it's just to click the Load button to the right and navigate to where you downloaded the file and select it + click ok and you have installed the custom layer style and can check it out and use it in your own projects.
Every now and then I (Erik, aka feneur) will post a new picture. While I try to make them "finished pieces" they're really more of experiments as I try to learn how to use different computer graphics programs.