OPEN WIDE
The most important tip to create great bokeh is open your lens to the fastest aperture. The faster your lens the better the bokeh you can achieve.
Fast prime lenses inherently have a shallow depth of field resulting in photos with blurry backgrounds. This is due to the larger aperture of the optics (i.e. f1.2, f1.8, etc.). For a more dramatic blurring effect, choose a lens with a greater focal length. See this example from Olympus Visionary Peter Baumgarten of the various bokeh effects possible with the new M.Zuiko Digital ED 45mm F1.2 PRO lens when taken using different aperture values.
GET CLOSE
Get close to your subject. The closer you are, the more bokeh will become apparent.
CREATE SPACE
Make sure you create space between your subject and the background. More distance increases your bokeh effect.
POSITION UP FRONT
Bokeh is not only for the background. Position some lights in the foreground of your subject and create beautiful bokeh effects close to your lens.