Have you ever asked yourself: What is lip liner for, anyway? If you feel seen right now, you are not alone! Though lip liner is a common makeup-bag staple, not everyone knows how to use the handy tool to its fullest advantage. That's why we called in the pros. Below, makeup artist and Byrdie contributor Ashley Rebecca has written a step-to-step guide to applying lip liner like a pro. Keep reading for her guidance, along with other lip-lining tips from top makeup artists. Meet the Experts First things first: Don't neglect your lips. It's common to have chapped lips from time to time and to experience dry, flaky skin. Yet focusing on keeping your lips smooth and hydrated will go a long way. There are some simple ways to ensure your lips look and feel hydrated. Start by exfoliating to rid yourself of any excess dead skin, and follow up with a hydrating lip balm (we love Sun Bum's Lip Balm SPF 30). If you're in need of a gentle lip exfoliant that still gets the job done, check out Fresh Beauty's Sugar Lip Polish Exfoliator.Prepping your lips at night is also an incredibly easy way to ensure your lips are on point 24/7. Slather on a lip mask before bed so you wake in the morning to a super-soft pout. (Check out some of our favorites here.) And a great thing about lip masks is that you can wear them at any time of day to give yourself a nice hydrating treatment. If you apply too much, just blot away the excess with a tissue or your finger. Everyone has their own unique lip shape, so the best thing you can do is to assess your own and really understand the shape before applying lip liner. Look in the mirror and ask yourself a few questions. What do I love about my lips? and What would I like to change about them? are two great places to start. You might have a fuller bottom lip and want to enhance the top lip shape, or you might want to create more fullness all around. Identifying what you already like, and what you'd like to tweak, is key when understanding how to get the most out of your liner.