Video Calls: In this new age it is easy to keep up long distance relationships with video calling. Skype and other companies offer video calls online where you can see and talk to your parter for free! This makes a long distance relationship much easier between those long stints of absence, and lowers your long distance calling bills if applicable.
Memories left behind: Often in long distance relationships, it is acceptable and even encouraged to leave things behind at your partners place. Having your own section in a bottom drawer, or an extra toothbrush leaves a subconcious idea that you are there more often.
Pictures: Keep pictures of the two of you around your room or house. Be sure to take lots of photos when you DO get to spend time with each other, and save them. Send them a picture of when you were first dating or of an important memory you shared. Keep thos good memories alive!
Care Packages: If your partner lives far enough away that you don't see them often, a care package is a great way to go. It can be filled with cute things such as a picture of yourself for their desk, a type of candy or food that you both enjoy, and even a stuffed animal to cuddle with while you are appart. To top it off, try adding a spicy romance letter for fun.
Surprise Visits: This is a fun way to spice things up in your relationship if you haven't tried it already. Although movies often portray it as a risky case of TMI, if you and your partner have a great sense of trust, there should be little to worry about. Contact one of his friends or family members to make sure he will be free and have them help keep his schedule open by pretending to plan something with them. (Slightly boring plans work well, so you get to be the super bonus suprise). Just make sure to be sneaky and make sure your partner does not have any previous plans before you arrive!
Something to look forward to: As a member of the long distance relationship community, you may already know that it is important to make your time together count. Try planning your trips to see each other regularly, such as bi weekly, monthly or as often as you can. Then plan an exciting event for each time you see them such as a new resteraunt, or a small day trip. Keep an eye out for amazing deals on flights if you fly to see one another. Major airlines are starting to partake in cyber monday deals.