What is a good general purpose setting to use for realistic looking drop shadows? Here are my current setting. I think there should be a value in spread. Not sure about noise.
X Offset: .0625
Y Offset: .0625
I don't think there is any single "general purpose" setting. Shadows vary depending on the light intensity and angle, and the height of the object above the page.
If you really want realistic shadows do it in Photoshop! Oh wait.. you said "drop", OK InDesign is OK for that but it's a seat of the pants things. For instance what the background is has an influence on the amount of noise.