Using PSP 9, but will work with mostly any program.
1. Start with your base. Don't sharpen or smooth anything.
2. Add a new layer filled with #004178, set it to exclusion at 100%.
3. Duplicate your base, bring it to the top, and set it to screen. Go to Adjust -> Hue and Saturation -> Hue/Saturation/Lightness and up the saturation to about 40.
4. Add a new layer filled with #69BAF9, set it to burn at 40%.
5. Add a new layer filled with #FFFFC0, set it to soft light at 100%.
6. Duplicate your base, bring it to the top, and desaturate it. Set it to burn at 64%. Sharpen this layer once or twice, depending on your image.
Let me know if you have any questions or if I did something wrong. I'd love to see what everyone comes up with. :]