When using the Camera app, having to tap the shutter icon on the screen can often cause camera shake or a lack of focus.
Instead, press either of the Volume buttons on the side of your iPad to capture your shot. Pressing these will help you hold the device more securely and get a steady shot.
If you have a pair of headphones with an in-line mic button, such as those that come with an iPhone, you can also press the volume buttons on these when they’re plugged in to take a picture.