Just let it go. Accept that you don't have whatever you're jealous over and forget about it. The more energy you focus towards it, the worse your jealousy will get. Focus on the good things in your life that other people might be jealous of!
ask you're self what it is you're jealous of and why, what does this person have that you don't? and do you REALLY want/need it?
The way I see it is jealousy often isn't really about them having something, but you not having it. Chances are, it's showing you something you want. Focus on how to work towards getting that for yourself, instead of the fact that someone else already has it.
