For any close-up shot, the emphasis should be on the subject, not the background. Thus the subject should be in sharp focus, while the background is slightly out of focus.

There are a number of ways to accomplish this, but the simplest is to move the subject away from the background. Don’t shoot a subject up against a wall.

Consider the top example on this page. The woman is so close to the background, viewers could actually can read the titles of the books in her office. It’s distracting.

In the lower example, the man has been positioned far from the background; thus the background is out of focus. A viewer can see that he’s in some sort of gymnasium, which is good. But the background isn’t so sharp that it attracts your your attention.