Personally I pretty much find myself taking pictures during the morning/afternoon and I also use a very subtle light mod (St. Claire's weather mod by brntwaffles) which is, to begin with, the best and most natural looking light mod out there imo. I just love the colors, not too bright or gloomy or yellow-ish.
Secondly if my game decides to put weird shadows I just edit them out. I don't know if that is an option for you but personally I paint over my sims face, clothes, hair et cetera (more or less heavily, depends if I want to sit down and go all crazy with my images or if I am just lazy).
These are the two things I do to avoid odd light in my pictures besides the usual stuff like correcting the colors, play with the saturation and stuff.