Black&White presets for Lightroom

Processing digital Black&White photos in lightroom could be hard task. The first way to create stunning BW is to just desaturate your photo, but it doesn't give good results. The better would be to desaturate each color channel separately to fully control processing. What could be helpful are also the lightroom presets with which you can process your photo by only one click. This gives awesome results and you can create many variations of you photography.