Well, Treewind and Mary, the matter of opera singing was brought up, there was some misinformation posted, and I wanted to set the record straight.   

If all you do is sing while doing the dishes, or croon lullabies to the kiddies, or shout out a chain-gang song while chopping firewood, or sing a few drinking song in the pub with your buddies, then that's fine. That's genuine folk music in its natural habitat. I don't think anyone really needs to prepare to sing, if that's the extent of it.

But the subject of this thread is "how do you prepare to sing?" The assumption of that question seems to be that the questioner has more that just a casual interest in singing, is singing regularly, is quite possibly singing professionally, and is naturally interested in singing well and preserving their voice over a whole evening's singing (not getting hoarse), and preserving their voice over an entire lifetime of singing (not eventually losing their singing voice entirely).

Whether it's an opera singer or a folk singer, singing is singing, hoarseness is hoarseness, laryngitis is laryngitis, and a shot voice is a shot voice. Opera singing is so rigorous and demanding that a singer who doesn't warm his or her voice up carefully before a gig won't have a very long career. The same holds for a singer of any kind of music. If you want to sing professionally (i.e., get paid to sing—even folk songs), then you would be wise to look at how singers who do the hardest kind of singing there is preserve their voices. I think it's stupid not to. Find out how the experts do it. Why try to reinvent the wheel?

And once again, taking a few voice lessons and doing some regular warm-up exercises before you sing are not going to make you sound like an opera singer. There are hordes of wannabe opera singers in music schools and going to voice teachers all over the world who wish that was all there was too it. If you weren't born with a larynx like Marilyn Horne's or Bryn Terfel's, you will never sound like them, no matter how many voice lessons you take or how diligently you practice.

Especially if you want to sing professionally, it's kind of counter-productive not to learn to use your musical instrument (your voice) in a manner that will allow you to sing the way you want to sing, sing easily, and sing for the rest of your life. And if you like to sing, but all you want to do is sing for fun, well, it's still not a bad idea. At least there will be less of a chance that you'll lose you voice later on. It depends on what you want to do.

I have no ax to grind. It's up to you. After all, it's your voice.

Don Firth