If Snapchat's canned effects aren't enough for you, there's now a simple solution: draw your own. Snapchat for iOS now includes a 3D Paint feature that uses the camera to draw augmented reality visuals on top of whatever you see, whether it's your face or a cute-looking car. It's a bit like Samsung's AR Doodle, but it isn't strictly locked to one platform.
The feature is available through a "Create" button in the AR Bar. You'll have to be patient if you're an Android user, unfortunately. Snap only expects to bring 3D Paint to Google-powered devices sometime in the "coming months," so you'll have to make do with the usual filters and other eye candy in the near future.