1. Recognize that you have become jealous
Recognition is the first step towards overcoming your jealous feelings. If you're in denial, it's unlikely that anything you do will help. So take a good, long look at yourself and see whether what you're experiencing is indeed jealousy.
2. Boost your self esteem
Oftentimes we become jealous of someone else because we're feeling low ourselves. Start to notice the things you're doing right in your life (and, yes, there will be some. Honest!). Gradually shift the way you feel about yourself and you'll notice the jealousy you used to feel start to melt away. Hypnosis and meditation can be a real help with this.
3. Turn off the news
Start by cutting out your daily dose of news. Whether it's delivered in the form of a newspaper, a personalized internet news feed, radio or television. Just quit your news habit. Most news is negative - that's what sells newspapers and gets ratings - and most of it concerns things you can't personally do anything about. If something major happens, one of your news watching friends will tell you. If it doesn't, the news will carry on being miserable without you. Use the time you've just freed up to do something more positive.
4. Avoid negative people
This isn't always 100% achievable but you can almost always go a long way to cutting out negativity or dramatically reducing it. Reducing your intake of negative people and thoughts will start you on a trend to feeling more positive about yourself. Which will help cut down on your jealous feelings.
5. Catch your jealous feelings
Start to notice when your jealousy takes over. The mere act of noticing it will help to diffuse it. Don't beat yourself up though - just because you've had a jealous thought doesn't automatically make you a bad person. Once you notice the thought, shift it. Do something to change the thought - minor changes work nicely for this. Give the thought a "Columbo" style overcoat or play magician and let it turn into a dove and fly away, taking the negative emotion with it. They're your thoughts and feelings. Start to take control of them rather than letting them take control of you.
6. Forget revenge
Revenge may sound sweet but even if you go through all the planning (which can be quite therapeutic in itself), don't actually carry out the revenge. The Law of Attraction works for revenge in exactly the same way as it works for everything else in the universe, so if you actually carried out your revenge you would likely find yourself the target of worse things yourself.
7. Talk your jealousy through with a friend
Make sure that the friend will be positive. Maybe sound them out first before going into a full confession. The act of voicing your feelings often allows them to disappear or at least reduce in significance. But don't share your feelings with the whole world, so keep them off your Facebook profile!