Check out motivational speaker DeVon Franklins' intervention tips.
The key to a successful intervention is the breakthrough. The breakthrough is the moment when the person you're intervening with clearly sees the error of their ways (in a way they hadn't before) and is determined to make a positive change to correct the problem, which they have been resisting to correct before. Here are some helpful tips if you feel that a family member, friend or loved one needs an intervention.
Be a Magnifying Glass, Not a Mirror
The main objective of a successful intervention is to be a magnifying glass for the person you're intervening with so they can see the issue clearer than before and be compelled to make a change. Remember: You can't change someone! Change has to come from within. So be careful to not be so forceful with your suggestions so that you come off like a hammer. If you act like a hammer and try to nail your point of view upon them, it won't work and the intervention will fail.