The magical effects of a well-worded and much-needed pep talk are so tremendous. You won't always have immediate access to the amazing word gurus in your life, so there are those moments when you'll have to rely on yourself for all the inspiration. There are more than a few pep talks to give yourself by the time you reach your 25th birthday, so that at least you're warmed up for the countless ones that lie ahead.
Pep talks can range from long to short and sweet. It depends on what you need the pick-me-up for and how much time you are working with. Whether you give this talk mentally or vocalize the heck out of it, it has a lot of meaning because it came from the heart. You internalize it because your words are unhindered, most times, by things that aren't always in your best interest.
Pep talks can be done anywhere you're willing to be honest and open with yourself. There's no script, but if you're being real, you'll never really say the wrong thing to yourself. In the mirror, in your car, or right before bed, having these pep talks with yourself before reaching quarter-life will help keep you on track.