I've never made any music videos, but I've watched a ton of them. A music video looks SO good when you match the action in the video to the music (a swell in music or lyrics like "he jumped into a volcano" and then the character on screen jumps into a volcano..). Especially for Sailor Moon music videos, people love showing those transformations or something that's totally not pertaining to the music used at all. Steer away from really crappy-looking text, too.

" If you CAN, please use high quality animations/videos with little to NO subtitles. I can overlook subtitles if the rest of what I've stated is exercised. I understand that some people have limited resources. Try to avoid showing one scene too long, as well, unless it makes a very big point for the video and song.
Can't help on the technical side but I hope this helps some. Try watching some videos on Youtube (good and bad) before tackling your own. Learn from others' mistakes! (If you'd like, I can link you to a WONDERFUL Sailor Moon amv to a Dido song. It's amazing work!)