Alright guys, thanks for all your help with this. So I'm getting that a mono delay 'behind' the vocals is a common way to go about this. But I'm still wondering about one thing. I often want to use the delay not as an effect but more to give a sense of space to the vocal, much like a reverb would do. Does a mono delay still do this? It seems hard to picture in my head because a mono delay doesn't make a 'space' for something to sit in, or does it?
To get a real sense of space, That's exactly why I treat a stereo delay the way I mentioned it in my previous post. And as Bouldersoundguy said, early reflections (or at least short delays) will be better.