Replicate traditional photographic techniques using step-by-step walkthroughs - part one: adding grain
METHOD 1: THE FILM GRAIN FILTER
Just as black-&-white photography has become synonymous with tradition, glamour, and sophistication, high-grain images engender a sense of gritty realism.
Traditionally, film grain is controlled by many factors, including the emulsion of the film (higher-speed films produce coarser grain), exposure settings, and darkroom processes.
In digital photography, setting a higher ISO rating on the camera will cause digital noise to appear in a similar way (though the effect is rarely attractive).
As a result, it can be better to recreate the effect using Photoshop's tools. The choice of image is important - some subjects fit the style more comfortably than others. B&W photography can be very flattering with film grain, as can images with simple or limited tones.
Portraits work well, as does anything with a pensive or moody theme. Ultimately you'll know if your choice of image works as soon as you see the effect.