It's funny, but I started composing (and eventually producing) music for film and video about 25 years before I started making actual videos. In any case, for me, the most important first step when starting a new video is still choosing the right music. More often than not over the past couple of years, I've either chosen something from my own growing library, or (because I can't help it) composed something new specifically for a new video project.
(Some of my music, most of it dance-y pieces that grew out of playing keyboards and percussion live for my wife Charmaine's SynergyDance classes in Washington, D.C. for a couple of decades, is available on CD Baby and iTunes. If you're interested in downloading or licensing any of the pieces here for your own use, please drop me a line.)