So you've been writing consistently, you've been careful not to back-edit, and you've made it all the way through your first draft. Now what?
Now . . . take a break.
I know the temptation is to dive right into rewrites and edits. You want to keep going. Inertia, right?
Only here's the thing: once you're done writing your story, you're going to be on something of a high (I know, I've been there). Or a low (I know, I've been there). Or both (I know, I . . . oh, never mind). To put it bluntly, you're going to be convinced that you created the greatest literary feat ever. Or the worst. Or both at the same time. Going into your story in that state of mind is counterproductive. You'll make mistakes. You'll miss things.
It's helpful to gain some emotional distance from your story. That way, when you start working on it again, you'll have fresh eyes. You won't be sucked in by your own genius or lack thereof.
This is definitely something that I both preach and practice. After I'm done with a new book, I put it on the shelf for at least a month, sometimes longer. That way, when I come back to it, I can more easily recognize the good stuff and axe the bad stuff.
So when you're done, take a break from that project. Work on editing an old one. Do research for a new one. But take a break. Your writing will benefit from it.