I would say think about the words. Think about what you want to get across in each line. Many times there are choices of emphasis. For example, in Lucy Kaplansky's "The Tide" you have a chorus of

I have nothing for you tonight
I have nothing for you tonight
I have nothing for you tonight
I have nothing for you.

When I sing it, I sing:

I have NOTHING for you tonight.
I have nothing for YOU tonight.
I have nothing for you toNIGHT.
I have NOTHING for you.

My choices are driven by what I hear as the meaning of the lines.

And if you think, you can avoid phrasing errors like the one Murray McLeod cited in "Raqlan Road."