I am not about to tell anyone how not to be distracted, because I happen to be the expert in being distracted and getting nothing done, hence the short length of this post. However, I can make two hesitant suggestions.
1) Force yourself to do something and in having a cursory go at it you may very well end up having a real revelation that you’ll WANT to focus on. Yay! If one of those doesn’t come after an hour or two, though, pushing yourself till writing feels like a chore never helped anyone.
2) Find some great music, turn it on, and let your mind wander to the beat. It works for me 90% of the time. And if you happen to have a really great inspiration song in your musical arsenal, feel free to share it in the comments! I’ll go through some of mine later this week.