I've been editing an interview with someone that said "um" after just about every sentence. As soon as you noticed him doing it, it became very annoying. I noticed it while I was recording the interview, but I wasn't in a situation where I could stop and suggest to them that they try and avoid doing it. Managing talent that is reluctant or nervous about appearing on camera can be a tricky thing and making suggestions like that can just end up throwing them off even more.
So I just let it go, hopeful that I could fix it in post. That was probably a mistake too, because there were a lot of them:
Cuts for first 30 seconds
Cutting out ums, ahhs and other verbal tics can be a real hassle. Not just because you have to get in there with the razer blade and slice away - and hope the audio matches up - but also because you have to do something about the video. If you're lucky and it only happens now and again, you can use a couple of cutaways. In some cases you can do a jump cut and live with it. A dissolve in the video can work too.
It's also interesting how the luck of the draw can have a significant effect on the audio transition. Clearly background sounds can cause problems, but so can run-on phrases. And sometimes you do a cut and for no apparent reason there's suddenly a popping sound that makes the edit stand out.
With about 30 edits, there were at least three where there was a noticeable pop at the transition. In nearly all those cases, moving the edit one frame left or right removes that problem.
It's an odd little thing; wish I knew why it happened.
You can also use an audio fade sometimes (particularly if the person is running words together, making it impossible to do a clean cut.) In those cases it's probably best to put the audio of one clip in one track, the other clip in a second track, and fade them in and out independently, rather than cross fade. You can then play with the fades of the two clips independently.
The real moral of the story; shoot lots of B-roll, you never know when you need it to cover up other problems!