Usually I do two things.
First I look at picture books. (never really outgrew that)
Second I print all those photographs I have been procrastinating on.
If neither of those work then I pick a project. There are lots of ideas on-line. The latest one has been to walk to a street corner and look all 4 directions trying to find a silhouette photo. It does not have to be good but it does have to fill the frame. Once I find it I can move around as needed to improve the framing or the composition. Then I shoot an entire roll, or at least 4 sheets if I am using a large format camera.
So far it has worked and I come up with some interesting photo opportunities I would not have found any other way.