The next topic is audio. I stressed lighting in the previous post and now I will stress audio because it is just as important as the imagery! I mean this both in the dialogue in your video as well as the music and the way your edit revolves around the music selection.
Audio is 50% of the video. If you're not watching the video, you're hearing it. Unfortunately, there are so many ways audio can be recorded poorly or not even at all during a wedding, so have as many sources of audio recording as possible! For weddings, we use two wireless microphones, two wired microphones, 1 audio mixer fed into the soundboard, and 1 room mic, propped up on a light that points to the speakers during the reception.
A few weddings ago I had a non-existant sound board feed. Fortunately the wireless/wired microphones covered the ceremony and the room microphone picked up the audio during the speeches. I have never been so grateful that we implemented backups!
Since audio is half of your video, you should spend at least half as much as you did on your lenses. No, your directional microphone on top of your camera will not capture good audio nor will your client be happy with your excuse when your wireless microphone feed goes bad. Don't skimp out on audio!