Just keep at it and concentrate, visualize that edge and bevel as you sharpen and keep in mind what you are trying to achieve. You need to do this on both sides, for me, I found that the hardest part, getting the other side of the knife to match the side I started on. I start on the right side of the blade at the tip and work my way towards the heel. When I do the “back” of the knife, I start at the heel and work towards the tip.
If your dull knives are no longer getting the job done or you're worried you'll cut yourself, you should sharpen your knives with a stone. Sharpening stones, also called whetstones, are made of natural or synthetic materials and they can be used dry, with oil, or with water. Once you've chosen a stone, simply run your dull blades over the stone until they're sharp again. If you've used an even hand, your knives will feel like new!
J. Kenji López-Alt is the Chief Culinary Advisor of Serious Eats, and author of the James Beard Award-nominated column The Food Lab, where he unravels the science of home cooking. A restaurant-trained chef and former Editor at Cook's Illustrated magazine, his first book, The Food Lab: Better Home Cooking Through Science is a New York Times Best-Seller, the recipient of a James Beard Award, and was named Cookbook of the Year in 2015 by the International Association of Culinary Professionals.