I love the look of paper lanterns, and there are several websites where you can purchase them for a little over a dollar apiece. If I look around, I might even be able to find other brides who are selling theirs after their own weddings, and save even more. These can make a very big impact, and with some LED lights and batteries, can even light up the reception as it begins to get dark. And after the wedding, I might be able to sell mine back to yet another bride, saving her a lot of money. All in all, it's a lot of look for not a lot of money.
I already said I was going to use paper cranes, of course, but I especially love the way they look strung up like this, at somewhat random intervals. This is probably going to be the main way I use them to decorate my reception site. They'll help define boundaries without hard and fast walls (this is the interior designer in me talking), and create a light and airy feeling all around. Again, a lot of look, not a lot of money.
Christmas lights can also give you a lot of pretty look, although they tend to work best on higher ceilings, where you're not able to see the individual lights so clearly. Additionally, you have to have electricity on site, something I'm not certain I'll have. Still, I have about four packs of these that I use for my holiday decor, and if they can help make my wedding look wonderful, too, why wouldn't I go for it?