There are many things that
you can do to come up with a good lyric for the bridge for
your song. If you have been writing in the first person (e.g.,
"I"), try switching to the third person (e.g., "He/She").
Another tried and true device for the Bridge is searching
through the Verses that you have written for the unspoken
element that ties the whole thing together. The Bridge is
where you can put it into words and sing it. The best part
of this device is, right after the Bridge comes the chorus.
Talk about a "Gotcha!"