After a separation, relationships can be hard to rebuild. The point of a separation is to see if you can live without each other and to get some time away from your problems to gain some perspective. Unfortunately, people tend to look at a separation as the beginning of the end for a marriage.
This doesn't have to be true of every separation - relationships can actually come out the other side stronger and healthier than they ever were before. The key to coming back from a separation is to fix the mistakes and problems that lead to the separation and make sure they stay fixed.
A lot of people make an effort to solve the problems to get their significant others back but fail to do the necessary upkeep. This is very much like going on a diet and then expecting to keep the weight off by going back to exactly what you did before. There's a reason why so many people gain the weight back, and it's the same reason there are so many divorces after separation; relationships need maintenance.
The very first thing you need to do to come back from a separation is to find out what the real reasons for the separation were. There will always be a superficial reason, some event driving the decision, but this is rarely the reason, this is usually just a symptom of the real problem.
If you don't find out what the true reason for the separation, relationships will always fail. This means you have to use the time away from the marriage to look at the problem with as much distance as you can. Your emotions will tend to mislead you.
Once you've found out what the problem is, you can begin to do the work needed to fix it. This is a process that involves your spouse; there are two people in a marriage and it takes both of you working together to fix the problems that lead to the separation. Relationships need to be a partnership, and this is a good place to start.
The good news is that fixing the problem is actually the easier part. Finding the problems tends to be harder, and that's the part most couples will get hung up on. The actual fix is usually just a matter of working with your partner to find the solutions and compromises that will allow you to work around the problem.
Like a diet, this will be a lifetime project, and it will involve change. The fact is that something was broken in your marriage, and the both of you are going to have change to make it work. This where most people go wrong after a separation; relationships have be treated as something brand new.
The best strategy is to treat the relationship as if it is something entirely new. Rebuild your marriage from the ground up, making sure to address the problems that how come before, but also addressing what has come before.
After a separation, relationships can be rebuilt. You just need to take the time and put in the work. Another good idea is to get some help; there are systems and advice available all over the internet that show you exactly what you need to do to fix your relationship and save your marriage.