You'll want to increase the refraction of the lamp shade to the highest seeting possible, give the specular halo a value of rgb 250 250 250 (very light grey, almost white), and enable blurry transmissions at 32 rays per pixel on premium rendering. Beware that this will KILL your render times, and you might as well enable blurry reflections and soft shadows as it won't increase the render time much more. (If you do this, make sure the shadow softness for the light you used it up at around 80 in the light lab)
Now the way bryce calculates the bluriness of reflections and or transmissions is via the brightness of the specular halo color for any given material on an object. Materials with a very dark specular halo (closer to black) with have little blurring of relfections or transparency, while materials with a very light specular halo value (closer to white) will have a high degree of blurring. Extreme values such as pure white will increase the plastic or metallic quality of materials. i.e. transparent objects will look like plastic or ground glass and reflective materials will reflect colors of nearby materials without appearing reflective. This is the KEY to realism as in the real world materials behave very much this way. Say you have a red ball next to a white wall, with a light shining on it. Now based on the scattering of the light from the sphere (all light that we see is reflected from surfaces of objects), the wall areas near the sphere will aquire a red tint, because the light is "leaking" from the sphere onto the wall. This is a very subtle property of light, but without it you can only go so far toward realism. What I do is this:
Turn on blurry reflections.
Edit the material properties for all materials that are not metallic or transparent (so edit any flat, "normal" maerials.). Give them a reflective value of 12 percent, and a diffuse value of 88 percent. Leave ambience at zero. Set the specular halo value to rgb 254 254 254, or one value less than white. Set specularity to less than 25. Now the reflection values should add the "light leaking" effect described above because they will reflect other colors in the scene. The high value of blurring (almost white specular halo) will scatter this reflection over a large surface area of the object, making it cease to look like a reflection and actually look like real light leakage. Keep in mind that if you actually want something to be reflective, make sure to set the specular halo color at or near full black, or the reflections will be blurred there as well.

Here are some examples:

In the above image, the bricks have a lightly reflective value to reflect the blue of the sky and to give detail to the shadows.

Blurry transmissions give the effect of frosted glass with specular halo values in the middle-grey range.

A scene utilizing both blurry reflections and blurry transmissions. Note, for the reflective sphere, the specular halo value was very close to black in order to keep the reflections in that object sharp. Render time was 38 hours at 128 rays per pixel.

Blurred reflections at high values really help to place object convincingly within an environment, lighting alone is not enough.

Blurred transmissions at very high settings will create great "plastic" materials, such as tomatos, human skin, candles, etc.

An early experiemnt, notice how the white walls acquire the colors of the red and blue walls. This is due to the blurred reflections.

If you are feeling adventurous, you can save a lot of time by lighting the scene with reflections. The most time consuming thing to render is shadows, so if you disable shadows and place a few lights well, the reflections will appear to be soft shadows at the lower ends of objects because no light reaches there, so these dark areas are blurred and become "fake" soft shadows. If you get good at this, you can render at 36 rays per pixel of premium settings in about a half hour per scene. Turn on shadows and watch the render time skyrocket to 6 hours or more. I hope this helps, let me know if you need me to go into more detail about anything.
-madmax