Mine is the idea of agon. Much as I don't want to be influenced by Harold Bloom, I see literary criticism as a struggle, a conflict. I don't think something is worth writing about unless it involves a significant critical problem. I don't even mind a polemic. I am motivated by ideas like having my ideas prevail, by competition with rivals and by struggles with the poetry itself. I want to win. Some of the negative emotions of the agon are actually motivating for me. For example, I might let my anger about weaker readings motivate me into doing something better.
I don't know if there is stupid motivational trick here. Maybe it's that you should consciously think of what your own metaphorical conception of your work is, clarify that to yourself. I think everyone has one, or should. Now once you have that clear, what are you going to do with it? What are the sources of power in the metaphor? What are the potential pitfalls?
In my case, for example, the idea of a struggle or agon allows me to excel in certain ways, to choose non-trivial critical problems, to have a stake in what I write. On the other hand, it makes me too testosterone driven, too angry and polemical. It's something that I have to consciously control in order not to let things get out of hand.