A blank page with unlimited options is harder than a napkin with a deadline.

Freedom without constraint does not produce more, it produces hesitation, because with every option available there is no reason to choose any particular one. A limit gives you something to push against and a point at which the choosing has to stop. What feels like a restriction is usually the thing making the work possible.

Invent the constraint yourself if none exists, whether one hour, one page, one color, or done by Thursday. Make it specific enough to be uncomfortable. You can always widen it later, and most ideas arrive after the narrowing rather than before.