A must do is something pretty relative.
It all depends on how badly you want your ex back, and how far you're willing to go to get your ex back.
Are you willing to move out of your comfort zone and make concessions which will have a lasting impact on your life? Rule No.
1 -- Declare a cease fire.
If you want your ex back, first thing you need to do is accept the fact that you're willing to concede a lot of arguments.
Make it crystal clear to your ex that you are not interested in going through the arguments all over again.
Next thing you can do is make sure that you're going to be paying more attention to your ex, if you get back together.
You can, and should, provide evidence of this by actually doing something your ex wanted you to do before you broke up, but you put off for some reason.
The fact that you remembered and went out of your way to do it will have a big impact on how your ex now thinks about you.
And nothing works better than communication.
After a time, couples get into the habit of making unspoken assumptions about each other.
If you think your ex now has many wrong perceptions about you, maybe it's because you didn't take the trouble to correct them.
If your ex doesn't know what you want and you don't know what your ex wants, then you're both throwing darts blindfolded.
Talk to your ex and explain where you stand on every issue -- clearly and explicitly.
And last but not least, physical attraction and personality plays a big part in a successful relationship.
Think back and look at yourself, the way you were -- when you first hooked up with your ex.
What did your ex like about you at that time? Have you lost some of that magic? If so, then maybe you should be looking at ways of improving yourself.
If you look good and feel better and healthier, then your ex will get the message.
Believe me, it works.
Physical attraction and chemistry can make people forgive and forget even the biggest slights and arguments.