I've been a photographer of model homes for well over a decade for several regional builders from
Memphis to Nashville. I often have to work with available light, making the best of whatever situation
I come across, then retouch the images later on the computer. Here's a few examples of some
typical touch-up work. Click the Picture, then Hover Mouse Cursor over it to view the raw "before" image.

As you can see by comparing before-and-after, I often correct for lens distortion when touching-up a photo. (Click the Picture, then Hover Mouse Cursor over it to view the raw "before" image)

Sometimes striking a balance across the tonal range is more of a goal than just brightening the shot.
(Click the Picture, then Hover Mouse Cursor over it to view the raw "before" image)

 
In this example I even had to replace a missing light bulb. Some would think this pic a bit overly sharp, but
as long as you're not making halos, go sharp! It's a lot easier later to soften the picture than to re-sharpen.
(Click the Picture, then Hover Mouse Cursor over it to view the raw "before" image)

 
A bedroom still life demonstrating just how far in the shadows an image can be and still deliver plenty of
usable detail. (Click the Picture, then Hover Mouse Cursor over it to view the raw "before" image)

 
Here's a fairly typical situation where I have one shot at getting the picture regardless of the weather, and just
have to make do at the re-touching stage. Trees were resculpted to eliminate annoying sky discrepancies.

(Click the Picture, then Hover Mouse Cursor over it to view the raw "before" image)