Someone said it's fickle like a woman:
well, I don't know if he is right
(and anyway I love them both)
but I spent a lot of nights just to find errors
on the images the day after.
In the long run you gain experience
and learn the way to get better results and minimize the problems.
I am neither an expert nor a professional
but I have learnt some useful expedient.
These pages for sharing them.