STEP 4: CUT, SPLICE, AND SYNC
Get a comfy chair because here is where the most time will go into your video. The more time you spend on this step, the better your video will look.
ACTION
The first and easiest thing to do once you start arranging your clips to the sound track is action sync. From your planning in step 2, you should have a good grasp on where the beat, symbol crashes, and dynamics are in your song. The trick is to make stuff happen at those times. Generally, the more stuff happens at these times, the better the video will look.
GAG ME
"Gag" sync (funny or ironic lyrics matching to the action) is more of an art form than action sync. For gag sync to work, the viewer must usually hear the words and then see the gag. The time between the word and the gag is where the art form part comes in. You usually don't want the gag and word to happen at the same time. This causes the viewer to go, "What was that? I missed it..." Give the viewer time to absorb the word and then anticipate the gag.
Also, don't over-use the gag. It may be great the first time and cool the second time, but after five or six times of the same thing, it's probably getting old fast. Try changing the gag around into something more unexpected.
LIP SERVICE
Lip sync can be easy or hard depending on the scene you choose to sync. Easy clips to lip sync are ones where the character speaking and the only thing moving in the entire frame is the mouth. Generally in these clips, there are two positions of the mouth, open and closed. Advanced (and better) lip syncing can be done with more mouth positions. To lip sync, all you have to do is isolate the open and closed frames and then repeat them with the words. The open position could be repeated for five or six frames and then two or three frames of the closed position. With more mouth positions, you can follow the dynamics of the lyrics better and add more realism to your lip syncing.
Hard lip syncing clips are ones where there is a lot of movement in the shot, either by the character or the background. In these shots, you either have to be lucky or do some major Photoshop work to get the sync right (most of the time it's luck). Basically, and this applies to the easy shots as well, if the mouth movement starts when the words start and the mouth movement stops when the words stop, the shot should look fine (or at least as good as the overdub version).
Mouth movements are not good when there are no words. Mediocre videos will usually make the mistake of having talking head shots during the solo of the song. It may be a crucial moment in the anime where someone is explaining something extremely profound to someone else. But to the viewer who hasn't seen the anime yet (imagine that, someone who hasn't seen the same anime you have!), the viewer is left thinking "I wonder what are those people talking about?" instead of paying attention to your video.
REPEATING
Another thing that is generally not good to do is repeating footage. Say you get through the first verse and chorus. After the second verse you get to the second chorus. Don't use the same series you did for the first chorus. Bad, creator, bad! Even using the same clips in different parts of the video is usually bad. The viewer is going to say to themselves, "you've been there, done that". There are some good uses, such as repeating a small segment in rapid succession for dramatic effect. Other than that, repeating footage in a video is considered bad.
EFFECTS
The last thing to cover here is digital effects. I know, your looking at this big pallet of effects and transitions, like a kid in a candy store, wondering how you're going to fit them all into your video. Don't do it! There are plenty of excellent videos which use few to no effects. Digital effects should only be used to help tell the story your video is trying to tell. Using digital effects for the sake of using them puts you video in danger of falling into the "Episode 1" category. (In case you're new to this planet, "Star Wars: Episode 1" was the much anticipated first prequel to the widely famous, and considered sacred, Star Wars series. It has some dazzling effects and cool ninja moves, but other than that, the movie unfortunately blows.)
I'm not just talking about cheesy effects either. There are some videos out there that have some spectacular and impressive effects, except there was to much emphasis on the effects and the video wasn't that good. The best example of the good use of digital effects in a video that I know of is "
Tainted Donuts" by Weibelius (Eric Kobet). It's chock full of effects and each adds to the telling of the story in the video.