Few things can be as striking to the eye as a beautiful black and white picture. It's simplicity at its best. There's a few things you can do and experiment with to find ways to add even more beauty and character to your art. I am going to go through some of my faves here.
1. Black and white with CONTROL.
Simply opening up photoshop and desaturating the photo will not bring out the best in it. There's so many factors to consider, even with the lack of color. A very good start is to open either the channel mixer and cross in "monochrome", or go directly to Image-adjustments-black and white (if you own photoshop cs3 or cs4). What you need to do here is to play with the different color channels. Move the sliders in different directions and keep a very close eye to your lights and shadows. Watch out for destroyed pixels and overblown highlights. Generally you can add a bit of extra contrast with a black and white picture so it will give you more room to play. Remember that there's no setting that works for every picture!
2. Black and white with a TINT.
Something I love to do after turning my photo into a well balanced black and white picture (see the step before) is to apply a color tint. This is very very easy and there's more ways than one to do it. I will tell you about my two favorite ways. Image-adjustments-color balance will open up a box with different color sliders. You can here decide what color you want more of, and by moving these sliders in different directions they interact with each other and can create many different beautiful tones. I think my most value tips here is to advice you to pay attention to both highlights, shadows and midtones SEPARATELY. You can create very nice split tones and even slightly surreal effects this way. If you like to keep your tint subtle (and I often do) it's enough to move the sliders just a tiny bit. Try moving different ones and see what you can come up with. The second option for a beautiful tint is to create a new layer and fill it with a color (using the color bucket). You can here have tons of control over the exact tone you want and even mix more than one. You can then experiment with the blend modes, with the blend mode COLOR in focus. It will simply colorize your black and white picture in whatever tone you pick. You can adjust the strength by moving the opacity slider.
3. Black and white with GLOW.
I talked about dreamy pictures before, and this is one effect I love to use on black and white pictures. Mostly cause the highlights are very defined and "open" in a well made black and white picture and it makes a lovely base for some dreamy art. Filter-distort-diffuse glow is one of my favorite filters to use here. It will not only give you a great amount of control over where you want the glow placed, it will also let you decide where you DON'T want it placed. The top slider has nothing to do with the glow, it controls the graininess of the picture. By moving it you can add noise to the glow and photo. Combined with each other it can give beautiful effects, especially in black and white pictures that flatter noise a lot more than color pictures does. You can combine this or replace it with some Gaussian blur on the blend mode OVERLAY or SOFT LIGHT. These blend modes will also make the contrast stronger so be careful not to go too far.
4. Black and white with subtle SEPIA.
A very popular effect that doesn't have to be used strongly at all is the beautiful sepia tint. By adding just a touch of it you can give your photo a hint of a vintage/old school feeling. Combined with some textures it can look even better! A quick way to a customized sepia coloring is to desaturate your picture and then open your color balance box (Image-adjustments-color balance). Add red and yellow to fit your taste. After this you can either keep the strength as it is or lower it. (that's why you should always duplicate your layer.)
5. Black and white with BORDERS.
Something very simple to spice up a picture is to add a simple border. Doesn't have to be fancy at all, just a simple white or black one, and if you want to spice it up some more you can use a texture as a frame that you masked out, and even create your own photo mask. There's also frames you can download, use through plugins or create yourself. Experiment and see what looks best on your pictures.
6. Black and white with VIGNETTE.
Vignettes can be soft or harder, blurred or sharp, black or white, round or oval....you have endless possibilities. Something they all have in common is that they have the possibility of adding depth to your pictures. A very subtle, soft, black one is perfect for balancing your black and white pictures. It helps the viewer to focus the eyes and it looks a lot more attractive.
7. Black and white with CLARITY.
Applying just the perfect amount of sharpness will bring out the best in your detailed black and white photo. Do NOT over sharpen, it never looks good. My favorite way to sharpen is to use high pass on a blend mode (such as hard light) It gives you tons of control.
Last but not least, shoot your black and whites with love and emotion! The best way to do this is to shoot with your heart, and have fun while doing it!