The photo above is a high key photo but you can see the subtle folds and movement details of the white dress. Detail does not refer the sharpness but the different hues of white make up the folds of the dress. Without these details the flowiness and pure elegance of the bride is devastating lessened. The ability to preserve the details in the white and blacks distinguish professionals from the newbies.
To get detail in the whites you must underexpose but becareful not to underexpose too much. There is a fine line between too much underexposing and the acceptable amount. This will depend on the lighting condition of you model and area AND YOUR CAMERA.
How do you know how much is too much underexposing? You need to do a few test photos by photographing a subject in white in many lighting situation and different degree of underexposures. Then take these images and use Photoshop to see how much you can lighten without the image colors/pixel breaking.
BTW, high end/professional DSLR camera have better chip which can capture more information even when underexposed - that is why they are much more expensive than the consumer cameras. This technique will not work on most inexpensive non DSLR cameras.
Below is the original file without any digital enhancement and it is property exposed for the white dress.
With this photo I can determine how much detail I want to preserve in the dress during the digital enhancement step.
As an editorial piece I have chosen to go in the art direction of expressing mood and pure emotion. I have made this the lightest as I could but also showing detail in the whites. I took it one step further and simulated the polaroid affect. This way I can place the caption as a handwritten label.
As you can see, there was good amount of digital enhancement work involved in the resulting photo. There is no easy way to achieve these results. Some of the things I used are Curves, Levels, Color Balance, Vignette, Pattern and Masking. Each image is lit differently and it just requires your time and patience to coax the effect you are looking for.
For me, I don't complete the work on one day. I tweak it then look at it again the next day to see if there are any way I can improve it. It takes me a few days to finally decided that the final photography is done.
Hope you like it as much as I do.
BTW, the jumping up and down was my idea...I couldn't contain myself and that was the only way I could express that.