The next stage of the process is to start thinking about what track you would like to make a music video for. What is important to realise is that you should pick a track that would lend itself well to task and NOT YOUR FAVOURITE TRACK.
Here is some criteria to help you think about your choice:
Try and find a track that doesn't have a video already, particularly a well known one. Your video should be original rather than a copy.
Find a track that has lyrics or music that make it easy to visualise potential content.
Lyrics are a big help as you can build your video around a performance, instrumental tracks need more abstract imaginary so can be a bigger challenge.
Don't choose a really long track - 3-4 minutes would be fine.
With this in mind: brainstorm a list of tracks and whittle down the list to THREE potential tracks.
For each one - embed the track onto your blog (soundcloud, youtube) and write a paragraph explaining why you chose it.