1. Get a flu shot - if you do not have an egg allergy then I suggest getting a flu shot. The flu shot consists of having the dead flu virus injected in your body, then your bodies immune system will start to create the antibodies needed to protect you from the flu virus. Now there is a side effect, it is possible to experience flu like symptoms for the first 48 hours of getting the flu shot, do not be alarmed that is your body recognizing the foreign invader and it is arming up to fight and create the antibodies needed to make sure you don't get the flu. You should feel fine after taking some advil and getting a good nights rest.
2. Wash your hands often and frequently.
3. Try not to touch your face especially your eyes, mouth and nose. These places are where the flu virus gets into your body.
4. If you work in an office, sanitize your desk. Make sure to wipe down the telephone receiver, your mouse, keyboard, and any handles that you grip during your work day. These are all culprits of where the virus can be lurking.
5. Wash your Hands.
6. Eat vitamin C. Either drink some orange juice, eat an orange, or take vitamin C. It helps boost your immune system.
7. Sleep at least 8 hours a day.
8. Make sure to keep up with a healthy diet. Eat at least 3 times a day and make sure it is balanced with 1/3rd protein, 1/3rd carbohydrates, 1/3rd healthy fats.
Staying healthy and making sure to take care of yourself so you don't get "rundown" will be the best way to protect yourself. As long as your body is strong it will be able to stay healthy, if you miss out on sleep and don't eat properly your body becomes weak and that is when foreign invaders like the flu will creep in and take over.