First step - forgive yourself. Just do it. Don't rehash what you should have done differently yesterday. Let it go. Today is an awesome new day, don't let the sins of yesterday pollute it!
Okay, now down to business. Fluids are key since extra salt, sugar, and alcohol can dehydrate your body.
1) Start the day with a tall glass of water or warm cup of any type of tea. Then continue drinking throughout the day, aiming for 64 to 100 ounces to flush out the pollutants from yesterday.
2) Plan to eat three meals, with lunch four hours after breakfast and dinner between 6 and 7pm. Focus on nutrient-dense foods that are low in calories but high in vitamins and minerals since Holiday fare tends to be the opposite: high-calorie and low-nutrient. Good choices are a salad with a variety of vegetables and an avocado. If you eat animal products, low sodium, water packed tuna.
3) Have an afternoon snack around 4 pm of green drink powder mixed in water or a smoothie. Look for one like HEY GIRL Cleanse that will help aid in digestion and gently remove 'guck' that may be hanging around in your gut from yesterday or weeks ago!
4) You can also have a whole-food snack after dinner if you are hungry. Example: non buttered popcorn, whole wheat crackers, almonds
5) Take a multivitamin, and at every meal pop a 1,000-milligram omega-3 supplement, which will help reduce the inflammation that can be caused by poor eating. (Talk to your doctor first if you are on any medications since omega-3s may interact with some medications).
Then back to your regular healthy diet tomorrow. Good job!