I think that's one of the reasons we join a community like this (forum). To become more motivated to complete tasks we've set ourselves and also to be inspired by other members work. I too, suffer from this phenomenon at times. I find that being in contact with like minded people provides some inspiration. Attending shows, exhibits, fairs, race meetings, relating to your chosen field sometimes provides the necessary motivation to proceed with the next phase of your project. Failing the lack of these aforementioned avenues, I sometimes, just start a new project, one that is smaller than the preferred one. I find that this gives you renewed interest in the primary task once the smaller project is completed. This practice, may have the undesirable effect of you creating endless new projects, but hey, otherwise you would be just sitting there procrastinating.