It seems like everyone and their sister are wearing birdcage veils lately. And it's easy to see why this style of veil is so trendy: they are SUPER cute! Not for everyone, either by personal taste or face shape, these veils will add a cute touch to any gown.
The easiest way to get one is, as with most things, to buy one. There are a ton of veil sellers online; two bigger websites are Something Bold and BirdcageVeils. Within the realm of birdcage veils, these suppliers have multiple styles, from not only with simple combs, to veils with flowers or feathers, to multi-layer veils with lots of volume.
Another source, and maybe one that's a little more fun, is to hunt for handmade birdcage veils on Etsy. I just did a search, and you can find birdcage veils between $130 and $5, depending on your taste and how much you want going on up there. My favorites are by sellers Joei Reed Custom Millinery (if you want to be unique, kick it up a notch with some color or a hat!) and Brenda's Bridal Veils (she has lots of ready-to-wear variety and she takes custom orders as well!).
Other than purchasing your birdcage veil, you could also try your hand at making it, if you're crafty (or even if not—it's not very hard to make the simple net-and-bobbypins style) or if you have a friend/sister/mother you can talk into trying it. The absolute best site that I found with directions was VintageSewing.info. There are step-by-step instructions along with old-school illustrations to show you what to do. Another site with directions is this personal site where the author describes how she made her simple net-only veil and has a little hand drawing to boot.
To make or to buy? That is a question you have to answer for yourself.