if there was no other camera at all to cut to and depending of the final output i may crop the image into a tighter shot to simulate a second camera.
I usually only do this if the final output will be in SD and i'm working with 1080p/1080i video since there's no quality loss. I do it on full HD projects only as a last measure and by cropping less so the quality jump is not too noticeable, but i usually try to avoid this option.
I sometimes use a quick 10 frame dip to white transition between thoughts, answers, sections etc. Rarely does the whole interview appear in it's entirety; there is always room to tighten up. You're doing the interviewed a favour. A lower 3rd with the question asked for the first moments of the answer is also nice.