First of all, you have to make sure that the music is not only going to reproduce the words, but also carry their meaning in the most active way possible. If music cannot contribute nothing special to the text, it is best left alone, prosaic. Because in art, anything not useful is best left outside the equation.
One of the most important things that you have to do is find the keywords of the text, meaning to find the most important words, the ones that you have to emphasize the most with your music, and then figure out how you are going to emphasize them, and in what way. Music is all about personality, every composer has to find a way to keep all other composers out of his grounds. So, try to find your own kind of language, and find your own ways of pointing out what's important. Non-musical elements are also acceptable, in order to attract attention to what you want, and carry the message all over the place.
And that's one other most important thing: the musical message! Often times, the message isn't even musical. That's okay. Although the message might not be musical, music might be the messenger. It is actually a very common idea, in the music world. You might, for example, write a piece that's trying to keep people away from war, and from fighting. That's a musical piece, of course, but its message has nothing to do with music. This is called an out-of-music factor, and it has been around for centuries.
In lyrics though, it is another story. Lyrics are always an unmusical factor. You may set them to music all you want, but in the end, they always carry a non-musical language. And that's the point, otherwise you wouldn't insert lyrics in your music anyways. What you have to have in mind though, is not to get too carried away with lyrics. Music has to come first! You may emphasize lyrics with your music, you should of course base the whole composition on the lyrics (because lyrics certainly preexist, you don't write lyrics on music, but music on lyrics), but the music is the one thing that should be projected the most!
So, get out there, find some lyrics, and convert them into the beautiful world of music!