Playing with white balance to create interesting images.
Gear Suggestions:
A camera where you can adjust the white balance makes life easier. This could be a DSLR or compact such as Nikon's new COOLPIX P7800 which has various white balance settings, including custom white balance if none of the pre-sets give you the look you're after.
Once you've found the camera's white-balance control, take a look at your manual if you're unsure where the white balance options are, do try the various settings on offer as each one will give a slightly different look to your image. Most cameras have the following white balance settings: auto, cloudy, daylight, incandescent, fluorescent and flash.
Technique:
Much of this is you playing with the various presets – or in Photoshop afterwards.
One of the most obvious is shooting with the incandescent setting in daylight to give blue-coloured images. In film days, fashion pros used to use tungsten-balanced colour film in daylight. With digital, you can try this without risking anything and if the effect looks wrong, switch back to auto white-balance and try something else.
Most cameras have the option of using Kelvin. You could set a low value and shoot in normal daylight. The effect can be very pronounced and will enhance the mood of suitable scenes. There is no right or wrong when it comes to experimenting.
With the setting on incandescent while it's still daylight. Giving off that bluish tint, but digital will be taking a risk. If this setting does not work, switch to an auto white-balance and figure out another way. It takes time getting use to a camera's settings. You can even play with the white balance on your RAW files.