I've done a long distance sort of relationship in the past when my ex was temporarily assigned overseas for 6 months.
Here' s what I did:
1. Communicate a lot. I started my morning calling and texting. We actually adjust our schedule since our time zone are 5 hours apart. so expect that your partner might be still sleeping when you wake up or you are sleeping when he finally out of his office at 6 pm his time
2. Schedule a date nights. well, your night can be his afternoon but it does not matter. You both are free perhaps on weekends. On date nights, you can talk non stop, watch the same film together or have meals at the same time.
3. I cook his favorite meal.
4. We pray together and read book to each other over the phone.
5. We remind and keep track of each other's fitness routine.
6. We renew the trust by talking about daily events.
7. Build up more trust by being transparent.
8. Surprise each other by sending gifts.
9. Never stop loving.
10. Don't ever give up.

Some times it work, some times it does not work.