Generally speaking, taglines aren't necessary. Luke Sullivan says, unless you can write a "Just Do It," just don't.
But here are two reasons portfolio students should practice taglines:1. You're going to have clients who ask for them.2. Taglines are just one more way to showcase how you think.When I'm asked to write a tagline, I sometimes begin by asking myself, "What is this? And what does it do?"The ultimate driving machine.The uncola.The king of beers.The antidote for civilization.Nothing runs like a Deere.It gives you wings.That was easy.Think outside the bun.It's everywhere you want to be.Just a few examples of good tags that answer the simple questions, "What is this? And what does it do?"