Hmm, look around on other videos, they have a bit of action, nice music that fits, some shaky things 'n' shit. Try to come up with an similar idea, work on the video for a week or longer so you get everthing rigth. Then show us your masterpiece!
The only prob with adding music is really if you intend to post it to youtube as then it can sometimes delete it even if you legally paid for the tune.
I you do use music then it's sometimes cool to synch the music with some of the beats or rousing parts of the song.
Here is my example using windows movie maker (which is pretty standard) that I made a while ago which starts with nice peacefull music and the action has has loud bashy music to try and make the vid feel more exciting.
I mainly made the vid change on the symbol hits or part of a lyric.
You may also find it takes a lot of recorded lfs action to fill the time as no one wants to watch a 3 minute vid of someone just playing lfs as we can all do that.
And of course your fist attempt may not be that good. (damn tlcook for keeping it) linky
But the main thing is to have fun making it.
Have a look at the vids done by other people on this website and see why people got 5 star ratings.
It's often quite simple things
Mood of the vid
Effects/vid editing
Quality of the frapsing
Whether the vid makes you feel anything good or shows something unique or unusual.
Type of music
Types of camera angle, again somethng different/unusual.
Whether the vid keeps your attention (I have an extreemly limited attention span)
Whether the vid is any fun
Just some random real ones I found that may or may or may not insipire you that combine a lot of what I listed.