As I mentioned, handhelds need to be fairly close to the subject's mouth--although you shouldn't have to block her face. You've probably seen rock stars practically swallow their handheld--but you don't need to get quite that close.

In the illustration at the right, you can see that while the handheld is visible, it is not covering any part of the subject's face. Also, there is a natural tendency to hold handheld mikes too far away. While this is less intrusive for your subject--and keeps the mike out of frame--the resulting sound quality will be poor.

Lastly, make sure you don't move the handheld around too much as your subject talks. Because if the distance to the subject's mouth varies as the subject speaks, the sound levels will vary--which can be a big problem.