No relationship is devoid of fights. In fact, when you don't fight it is obvious that you are still tip-toeing around each other. It speaks of emotional distance or pretense, which are both toxic.
Since fights are inevitable in relationships, wouldn't it be best to know how to fight? The truth of the matter is that I can tell you not to say hurtful things to each other and to take a time-out when things are getting out of hand. but these pieces of advice don't always hold up in the heat of things.
The fact that you are fighting means you are already very upset. So how easy is it to not say hurtful things?
However, if you are able to control yourself and not say things you will regret, good and fine. If you two have found that walking away and revisiting the matter later always works best then go for it. However, for those that struggle with these two, let us focus on rebuilding the bridge. The deed has already been done and the fight was terrible, what do you do?
My advice is simple. First, don't let the gap widen. Once you realize you messed up, go back to each other and apologize. Secondly, reassure each other of your feelings. Don't let your partner remain in doubt or allow the bad things you said during the fight remain unaddressed.
As a preventive measure to avoid explosive fights, maintain respect and honesty. When you respect each other, it becomes difficult to say nasty things to each other even in a fight. With honesty, you always say when something hurt you rather than wait till it builds up before speaking up.
Lastly, know the signs. Watch yourselves over time to know the triggers and signs of a big fight so you can deal with it before all hell is let loose.