Here’s my fourth free Lightroom 5 preset, Silhouette. It’s a fairly straightforward black and white preset that works especially well for partial or whole silhouettes. Depending on the starting brightness of the photo, you might want to adjust the strength of the silhouette effect by adjusting the ‘blacks’ control in the develop panel.
Here’s the download: Lightroom 5 Preset: Silhouette
To install it in Lightroom, simply right click any preset, select import, and then select the downloaded preset file.