Tutorial!
For no particular reason, I decided to post a small tutorial. :)
This is how we'll be progressing:
----> 
First off, I used Photoshop CS2 to create the icon. It should be easily translated into lower versions of Photoshop or Paint Shop Pro. :)
With that said, let's begin!
Okay, now I know I'm not the best at explaining things clearly, so I made this to help:



I hope you can apply some of this in your icon making! :)
Enjoy.
This is how we'll be progressing:
First off, I used Photoshop CS2 to create the icon. It should be easily translated into lower versions of Photoshop or Paint Shop Pro. :)
With that said, let's begin!
- For this icon, I used one of my own caps (its Rose!). I cropped and sharpened it to my liking, and am left with a base:

(Sharpen is found under Filter-->Sharpen-->Sharpen.) - To brighten it, add a Curves Adjustment Layer. (Layer-->New Adjustment Layer-->Curves...)
I fiddled with it a bit and created two points. (To create a point, just click the line!)
The first point's Input was 176, it's Output 250.
The second point's Input was 26, it's Output 78.
Curves is the best brightener, in my opinion. This way you don't need to duplicate your background layer several times and set them to Screen.
Your icon should now look like so:
- Create a new layer. (Layer-->New-->Layer). We're going to use a handy trick to create an image of the icon as it looks when merged, without actually merging anything.
After creating the new layer, press Ctrl+Alt+Shift+E. Ta-da! - Duplicate the "merged" layer, and set it to Screen. Opacity 24%. (I'm very nit-picky when it comes to icons and such, so if you don't want to add a Screen layer, then don't! It's your icon, so do whatever you think looks best.)
It now looks like this:
See? Not too much of a difference, but, again, I'm nit-picky. - Create a new layer, and use the Paint Bucket tool to fill it with a light blue color. I used #DAF1FD;

Set it to Color Burn, opacity 100%. - Create another new layer and use the Gradient Tool. I used two colors; #DAC693 and #D3723F.

Set to Soft Light, opacity 47%. - Duplicate the "merged" layer, and move it so it becomes the top layer. Set to Soft Light, opacity 24%.
- Create a new layer, and fill it with the same light blue color. (#DAF1FD)
Set to Soft Light, opacity 100%. - Duplicate the light blue layer twice, setting both to Color Burn, opacity 100%.
- On a new layer, I used a texture by
77words.

Set to Soft Light, opacity 100%.
(I know, I know, enough with the Soft Light already!) - Okay, almost done. I wanted to get more red into the bricks by Rose's face, so on a new layer I used a nice red color (#ED0101) and painted them a bit.
It turned out looking like this:
I set it to Lighten, opacity 100%. - New Layer. I used another texture by
77words, and set it to Screen, with an opacity at 100%.
It covered Rose's face a little, so I erased part of it.
---> 
- I duplicated the "merged" layer again, brought it to the top, and set it to Soft Light. Opacity 43%.
Your finished result:
Okay, now I know I'm not the best at explaining things clearly, so I made this to help:
I hope you can apply some of this in your icon making! :)
Enjoy.