I agree with all the above, particularly Genie's comments about not being tied to a set pattern for every verse.

If I'm having trouble with a particular song, I go over each verse like this:
- read or recite the words (line by line, if necessary) as if they were prose, until I've got them into a 'natural' rhythm
- sing the words to the notes of the melody, but with the same natural rhythm, ie not thinking at all about the beat, bar lines, etc
- start to fit the words to the rhythm of the song, varying the rhythm to put the important words at the points in the bar where the emphasis is (or sometimes varying bar lengths to fit the natural emphasis)


I don't accompany myself (not a good enough instrumentalist), but if I did, I wouldn't start to add that until I was completely happy with how the words were fitting. On the few occasions when I've had someone else accompanying me, the instrumental part has been a very late addition.