Pioneered by the likes of Wim Crouwel and 8vo, using typography as the main focus point in place of an image is a very effective means of getting a message across. Type used in this way is popular today across a range of campaigns and is easy to achieve in Illustrator.
As well as experimenting with large headers by modifying letters, colours and so on, you can use type to mask over elements of your design. The effect can also be used to enhance the meaning of the wording. For example, you could mask an image of a fish with text saying 'fish' and then put a Fisheye Warp filter on the text.
As well as enhancing the meaning of text you can hide it and make it really subtle, creating a watermark effect by building up layers of masked images. In doing this you'll see how interesting effects start to happen when letter forms cut into your images.
In this tutorial you'll learn how to create the example image above. You'll see how easy the main masking technique is to follow and how it adds another essential string to your creative bow.
After the image is done, you can build up layers and experiment to learn how the effect can be used in different ways. But, as with all design treatments and styles, the key is not knowing how to use the effects; rather it's knowing when to use them.