In reply to Phill Mitch:
Lots of good ideas on here, and everyone is different so you will have to experiment. From my personal experience however:
1. Do the kind of running you enjoy. I'm lucky enough to live in the mountains so mostly run scenic trails, which is often enough of a motivator, especially this time of year when the weather is great. Grinding out on the road is sometimes necessary but day in/day out it would drive me mental.
2. Run with a dog. I've got a border collie who now basically expects to come running with me if I so much as open the cupboard with all my running clothes, and still needs walking if I don't feel like running, so 9 times out of 10 I might as well put my trainers on kill two birds with one stone.
3. Break up your training. I split my year into 4 or 5 week chunks and try to target a race at the end of each one so I have mini goals. Then after the race I take a week 'off' were I only run a few tiimes and do other things to get refreshed, and not plateau.
4. Record your runs. I use Strava and now have 5 years worth of running date. Its great to see progress and easier to not kid yourself that you're doing enough. I'm a bit of a geek and love the stats - there aren't really many people near me to compete with on segments but just seeing progress in terms of improvement is motivating enough.