Warm-up routines and rituals are a great way to overcome inertia and ease into productive work. Natalie Houston suggests setting or revisiting goals by writing them down in an idea notebook as a way to kick-start the creative process:

I’ve found this to be a helpful way to get focused and in the right mental state for writing. Sometimes I just restate the key ideas for a project (“I am writing about X in order to show Y”); sometimes I set a specific goal for that morning’s work (“Today I want to figure out . . .”).

See the original article, Why I Keep an Idea Notebook.