Can you really be friends with an ex? I honestly think you can it just has to be done in the right way. Not all romantic relationships are meant to last forever and just because it doesn't work out it does not mean you have to lose that person from your life. Sometimes there is no animosity and you and your partner simply realize you aren't compatible anymore.
Once your relationship has reached its end, its beneficial for both parties to spend some time apart before trying to be friends. This time is essential because it will help to clear the air of any tension that has been left as a result of the breakup. After enough time has passed you and your ex should discuss whatever grudges you may have so that you both can start to gain some closure. If you are ever going to be able to have a functioning friendship you need to let go of whatever unresolved issues there may be. The early stage of a breakup is meant for personal healing, this is not something that can be forced or rushed.
A tricky issue when trying to be friends with an ex is the extent of how much contact should take place between you two. It's hard to break the pattern of consistently talking throughout the day, but this is vital to moving on. You also have to allow the friendship to grow on its own. The relationship between the two of you is now completely different so of course the manner in which you communicate will be as well. Neither of you are going to hear about each other's dating life right away for a very long time. You need to avoid things that would bring jealousy into play.
It is important to keep in mind all of the good memories the two of you shared together, this will make it easier to transition into friendship. By focusing on the good times you allow for a positive, constructive environment.
When trying to develop the friendship it is essential NOT TO SLEEP WITH THEM. I know it's comforting and familiar, but that will dredge up past feelings and just make it harder on the both of you. It can also cloud your judgment and give you a false sense of hope for getting back together. If one of you starts to develop more than platonic feelings for the other at any point, you need to take a step back and re-evaluate what is going on.
Some people do eventually get back together but this is not advisable when trying to first develop a friendship. Clearly defined boundaries are the only method you can maintain a genuine friendship with a past lover. You need to keep in mind that your relationship ended for a reason.
Honestly, you do not always have to burn the bridge between you and your ex. If you have overlapping groups of friends, remaining civil with your ex is beneficial, so if you run into each other there is no awkwardness. Relationships that ended as a result of cheating or deception are different than simply realizing you two are not compatible anymore. In situations such as these it is inherently more difficult to remain friends.
The idea of remaining friends with an ex sounds like an ideal situation, but the road it takes to get there is filled with obstacles. You need to work actively on it so that both parties feel comfortable with the new direction the relationship is taking. You must be prepared for what you might face and how the two of you are going to deal with it.