Next you should see the controls for the Brightness/Contrast adjustment. This is subjective, so feel free to experiment with these values to get a "dreamy" quality that you like. I've boosted the brightness up to +15 and the contrast to +25. When you're happy with the values, click OK.
Essentially this is all there is to it for the dreamy effect, but I'm going to go on to show you how to give the picture a softly fading edge effect.