Now I'm not for one second suggesting that you don't cry and let it out. But what I am saying is that you're emotional break down is not something that your ex needs to see. You may think that it will help you cause to break down on the phone with your ex. However, if this approach does work for you to get your ex back, they'll be coming back due to guilt and no strong relationship is built on guilt.
SUCCESSFULTIP #2 Don't smother
Let your ex have some space to breathe. It can be just was they need to realise how important you are to them. Allow there to be some time without any communication. Use the time to reconnect with your friends, evaluate the things that were great about the relationship and do tip 3.
SUCCESSFULTIP #3 Understand the root cause of the break up
Take some time to evaluate the cause of the break up. Understand how you may have contributed to your ex's decision to break up. This learning will be essential when you get back together to ensure that you don't make the same mistake again.
SUCCESSFULTIP #4 Control your emotions
A break up can have you on an emotional roller coaster. Don't let your feelings impede your chances of getting your ex back. The last thing you need to do is shout abuse down the phone saying things that you know you'll quickly regret
SUCCESSFULTIP #5 Plan your interaction
Having followed all the above tips especially and given your ex sufficient space to begin to miss you; plan and organise an event where you can meet up and talk.