I have always found that, like a few others here, goals help to keep me getting out the door. The goals I set aren't always the most 'normal' running goals. They are sometimes typical running goals you hear; hitting certain mileage, training to run a time in a race, running a specific races, etc. but some of the goals over the years have involved getting together with others or seeing new places.
I once ran with a different friend or acquaintance each day for a month. Why? Just to switch things up. I was over the whole running by myself routine that I just started making plans (this took enough planning that it made it then want to run alone for a while too ). But the point was to give myself a reason to get out the door and not give in to the desire to sit around after work and be lazy.
Good luck! Keep on going with whatever gets you going!