I have been using the Manual mode ever since I picked up my Nikon D3200 about 6 months ago. I am pretty well versed with the exposure triangle & how to use it.

However, recently - I am starting to discover flash as a non-evil thing. And reading the theory about it, has left me confused.

Everywhere I read, people always say...

Situation : subject is facing camera with sun in the background (bright background, dim foreground)

 1. First expose properly for the ambient/background
 2. Then expose for the subject/foreground

What does this really means? 
Should I select a focus point on background, adjust my exposure & then focus on my subject again & then adjust the flash compensation to adjust for proper exposure? (this might mean multiple photographs till I find perfect exposure).

It would be great if people who are well versed with flash photography could answer this for me.

Thanks,