One fast and simple way to make your photos more interesting before turning them into black and white, is to use so called Selective black and white. In other words, some object will retain its colors on black and white surrounding that brings it more out / makes more noticeable.
1. Open your color photo in Photoshop.
2. Use one of those many selection tools to select object(s) that you do not want to turn into black and white.
3. Press Ctrl+Shift+i (in Windows OS) to invert selection.
4. Finally, use black and white conversion tool to loose colors (you can find some B&W conversion methods mentioned HERE)
Easy, wasn't it?