First, I have to say that being in a long distance relationship in this age of crazy-awesome technology is far better than back 30 years ago, like when I was dating and all we had was the United States Postal Service! Gesh, I'm old! Ha ha!
This is the MOST important element that must be present for a long distance relationship to work, and work well. In fact, this may be the most important element needed for any relationship to work well and be healthy. Without 'trust' there will be constant discord in the relationship. Suspicions run high in relationships where trust is not present.
Text, email, phone call, messenger, letters (the old fashion ones). Of course communication is important in all relationships, but especially when you are far apart it must be intentional and frequent and consistent. Never leave each other hanging!
3) Daily Updates
Now with texting, facebook, snapchat and every other social network you can keep each other updated on the little happenings throughout the day. This keeps your partner in the know with each facet of your everyday life.
4) Be quick to forgive.
No one is perfect, so give your partner a break and be quick about giving forgiveness! You will need it soon enough, so be generous in giving it!
5) Be quick to say, "I'm sorry!"
I was taught growing up we should always be quick to say, "I'm sorry" especially if and when you are the one in the wrong. Make amends! There is nothing more toxic than bitterness, or holding a grudge. Apologize when you are wrong.
I believe there is only one option when it comes to trust, you give it until it is broken. When it is broken, then you must rebuild to a place of trust again (if you chose to walk that road), but that may take some time. And it will definitely take some hard work, oh, and patience!
Refer back to #1 & #6