The hardest thing a writer can do is set aside their work. It’s like being without coffee for 72 hours! But, hey, the benefits far exceed this ‘cold turkey’ episode.
For one, you gain a whole new perspective on the writing that wasn’t there before. You get to read your writing like… well, a reader and that’s the advantage to setting it aside. You want to see how well your work holds a reader’s attention and interest to keep turning the page.
Two, it’s easier to look at the mistakes. In order to revise and edit your writing, you need to be able to see where you need to cut/paste/reword/etc. etc. etc. (there’s a lot to be done, trust me). It’s like a doctor who needs to do surgery. How can the doctor proceed without cutting the patient open? When the stiches come off (or disappear), the result is far better writing.
Third, you stop making the same changes over and over. If you ever have used an eraser (funny saying this, but it’s true in this present day computer infested world, but I digress….), you will often find yourself writing over the same recently erased spot.
The question is: how long should a writer set their work aside?
This is the tricky part. Some writers set their work aside for a month before looking at it again. Others set it aside for three months. Still, others wait six months. Maybe it all depends on other projects writers are doing. The important thing is to find what works for you. It’s like diets and everything else in life: it’s got to fit the individual. Have you found what fits your style?