You should always have ambient occlusion setup on:

1) The walls
2) The floor
3) Carpets that lay over the floor
4) The sofa/chairs/desks/flat surfaces where objects will rest

Then make sure you have ambient occlusion enabled on one of your lights. 

This is a bare minimum requirement for a decent looking scene. What do you guys think?

Well, in my experience, adding AO to a wall has an awful effect on it (I'm sure I'm not using the correct settings, just got to experiment more).  Also, if you have AO added to all your objects/people in the scene already, I don't believe there is a need for also having it on a light too. 

From what I have seen lately in images (at various websites), I think folks are going a little overboard with the AO.  It should be subtle.  Otherwise, you end up with a gray blotchy messes.

 Agreed. AO is for contact shadows and crevices primarily. I found it became much better looking by adding falloff.

*Agreed. AO is for contact shadows and crevices primarily. I found it became much better looking by adding falloff.

Interesting. Got a screenshot?

Quote - Well, in my experience, adding AO to a wall has an awful effect on it (I'm sure I'm not using the correct settings, just got to experiment more).  Also, if you have AO added to all your objects/people in the scene already, I don't believe there is a need for also having it on a light too. 

From what I have seen lately in images (at various websites), I think folks are going a little overboard with the AO.  It should be subtle.  Otherwise, you end up with a gray blotchy messes.

You're right it has to be subtle.

In the material editor I click "setup ambient occlusion" under the Wacros (on the right).

• Ambient Occlusion Node
  Samples: 3
  MaxDist: 2
  RayBias: .1
  Strength: 1.0
  Those settings work pretty good for me.  I use those settings on tables, walls, surfaces, sofa, carpets.  

Quote -  Agreed. AO is for contact shadows and crevices primarily. I found it became much better looking by adding falloff.

Falloff? :)

I'm good at falloff in real life, but what does it mean in this context, please?

concur if you are adding AO in nodes, not needed or desired in lights.

With AO in nodes, you have to engage raytrace, remember.

I use Occlusion Master. Great tool.

::::: Opera :::::

dimension3d has also got a script for automating the application of AO nodes to posersurfaces.
maxdist is a property of some poser light types and the AO node, hence we'll await further word
on  the use the term "falloff" in regard to FFRender.

PoserPro render
one fill light
two lights positioned close together both with raytrace soft shadows
AO in nodes on everything
scene rendered with Firefly
agressive AA settings
size: 960x540 (1/4 HD cell)
rendertime: 1 hour 12 minutes
Core2 Quad Q6600
4GIG RAM
Fast HD
XP Pro 64 bit

I like raytrace soft shadows in Poser. I have stopped using shadowmap shadows.
I very much admire the competence with which Firefly executes the AO, for instance at the base of the dresser where it meets the floor, and of course under her foot.

There is an error in this render. Rather than get rid of it in post-processing, or re-rendereing, I have left it in place for you to see........There is just a little too much light/specular on the back of her right leg, and where the leg meets the cloth....the AO is too strong.

I heart Poser for this kind of work.

::::: Opera :::::