Turn on Ambient Occlusion in the Settings, that should help at least a bit. That being said, an overhaul of the current implementation would be nice with more options like radius, number of samples etc, but I can understand that it’s not currently on the list of urgent features.
On a side note, a while ago I figured out how to change AO settings manually but the file structure seems to have been changed. Does anyone know where the mentioned file went? I’m a bit out of the loop. Edit: Found it and updated it to make it clearer.