If you've ever had to edit a ton of footage with dialogue, you know that it can take forever to find your in and out points. You could scrub through your timeline to hear when each line begins and ends, which, again, can eat up time that you simply do not have, or you can take a much easier route by using the waveform in your NLE. In this video, Caleb Pike of DSLR Video Shooter shows you how to use waveforms to edit your dialogue faster. Check it out below:

This approach can be a lifesaver if you're trying to edit within tight time constraints, but it does require you to get comfortable with waveforms. Luckily when it comes to this particular job, it's really simple. 

The first thing you can do is start broadly trimming down your timeline based on the wide peaks and valleys in the audio on your timeline. If you look at your waveform, you'll probably see a bunch of open areas that don't have any audio—you can just start cutting those out. Next, you'll want to do some finer cuts by zooming in on your timeline to see smaller valleys. Though you may not be able to make cuts at these points, they serve as good indicators that there might be something there to take a closer look at, whether it's a flubbed line, off-camera dialogue, or just dead air between thoughts.

You can also use waveforms in this same way if you've got sound from a slate marking either the beginning of a take or immediately after a flubbed line. These areas are marked with a spike in the audio and are easy to find, which is why you should always use a slate or a hand clap to mark the beginning of a line delivery, especially if you decide not to cut the camera and start a whole new take.

Source: DSLR Video Shooter