When an oven is heating up, parts of it closer to the coils are hotter. Therefore, sticking food into the oven will cause some parts to get charred even as parts remain uncooked. We pre-heat an oven because the heating process interferes with the baking.
When we are drafting a letter, an article or a presentation, it is tempting to edit as we go. We fix words or sentences, align and format boxes on slides and rewrite paragraphs in the process of composition.
However, the process of editing interferes with drafting. Editing halts the mind and breaks the flow of its ideas. Much like an unevenly heated oven, it causes the product to be well done in some parts while leaving them half-baked in others.
Draft your creations to the end before giving into the temptation of refining them.