The easiest way - eat fruits, vegetables, nuts/seeds, and meat; don't eat things that come in a package and have an ingredient list that lists more than just the item (ie - sometimes peppers are in a package and have an ingredient list that just states "peppers"); and avoid "gluten free!" products (they often have a lot of crap in them and aren't really worth it). Consume dairy if you can tolerate it, but remember that casein sensitivity is often found with gluten sensitivity. Stick to the whole foods on the perimeter of the grocery store (or, even better, forego the grocery store for farmer's markets, farms, and butcher shops).

Eating out is where it gets hard. For that, scout ahead and find the places that are either going to naturally be gluten-free, or can properly accommodate it. Ask for a gluten-free menu, or check out their website for gluten free options. Make sure you make your dietary requirements known and make it known that you're intolerant. Don't be afraid to stand up to those who treat it like you're just following some fad. Avoid anything fried, as it's usually breaded, and even if it's not breaded, it's usually fried in the same oil as breaded items. When it doubt, go back to the basic foods - grilled chicken/steak, egg dishes, steamed veggies, etc.

Check out websites and cookbooks that follow things like Atkins, Paleo, ketogenic, or raw vegan diets for meal ideas. These are often safe options that will require little, if any, altering, because they will by nature not use grains for a variety of reasons.

If you do find yourself wanting to include things like baked goods into your diet, look for recipes that use non-grain flours, like coconut flour, almond meal, or tapioca starch, or flours from grains that aren't typically cross-contaminated by gluten grains, such as rice flour. Almond flour is also a popular one for crusting chicken.

If you get packaged food, try to find companies that specialize in gluten-free, or at least that process their gluten-free products in exclusive facilities. For example, Moondance Desserts and Enjoy Life are two companies that sell things like chocolate chips, cheesecakes, cookies, and brownies that are gluten free and made in exclusive facilities, so cross contamination is pretty much non-existent (if it happens, it would have to be in their suppliers).