I've always liked the idea of gathering together and displaying a lot of something. In C.S. Lewis' The Magician's Nephew, there is a place called The Wood Between the Worlds. I've always wanted to create the feeling of that place in a central hallway, by lining it with pictures of doorways--inviting, welcoming, light-spilling-out-of-them, hospitable doorways.
I went to a basement restaurant once, where the ceiling was covered in upside-down umbrellas, with light shining through them. I've always liked umbrellas as accessories. They're so protective and covering--like being under the wing of a protective mother bird--and something about their shape suggests that they are glad to do it.
Candles are lovely in large quantities because they begin to resemble stars or campfires, which is very welcoming and human. I still use white Christmas lights too. I think I was supposed to have given these up after college, but they are still lovely. They succeed in having lots of little points of warm light, like candles, but have the merit of doing so with less mess. They are also lovely strung around a porch at nighttime.
Having a lot of ceiling lanterns like this could make for an interesting hallway as well.