Two beliefs appear constantly in writing workshops. Some writers think they cannot begin until the reading is done, the semester has quieted, and the calendar has opened up. Others think the project must be important enough to justify the time it takes. Both beliefs protect the writer from producing a weak draft, though weak drafts are usually where the work begins.
Perfectionism during drafting applies evaluation criteria too early. A first draft needs to exist so that revision can happen. Academic writers often have strong evaluation instincts because they are high achievers with a great deal at stake. Those instincts can interrupt drafting before there is enough material to assess.
One useful approach is to set a modest criterion before starting a section, such as writing an introduction that states the argument. Once the section meets that criterion, move on. A specific target gives you a reason to stop that does not depend on the draft feeling finished.
Writers also need to stop revising. At some point, another reader will be more useful than another hour with the same paragraph. A draft can be ready for feedback while remaining incomplete and open to criticism. That judgment can be difficult to make.