The Duct Tape Method
That one moment when you know exactly what you want to write, you know where the story is headed, you know your exact playlist and have the songs memorized and sing them to yourself while you plan...
Buuuut you have no idea how to get from Point A to Point B.
Point A laughs at you while Point B just stares at you sadly. Why aren't you over here? it seems to ask.
Oh, the anger and despair! Why, oh Muses, must you torment me so?! Why?! No amount of fast-paced cinimatic fantasy action music can clear this unseemly and soup-like fog that clouds my mind! Oh, woe, woe! Ok, so that's a bit dramatic. But it's true! You have a wonderful story planned out, but you have no idea how to get from the first line to the gloriously epic part in which your hero realizes their destiny. It's like you're standing on a bridge and can see the other side, but there's a gigantic hole in the middle of it that you simply cannot cross.
So what do you do?
You reach into your magically expanding bag of wonders and pull out plywood and duct tape. smack that over the hole, and get to the other side.
My point is, the writing you use to bridge the gap from Point A to Point B does not have to be perfect. You will write, and rewrite, and rewrite some more. You can come back later and fix your bridge with better, stronger materials. But you did what you needed to do to cross. (And this, children, is why you should always buy and carry a magical expanding bag of wonders. They are lifesaving, especially when one is faced by man eating trolls.)
So go forth, Writer! Wield your duct tape like a mighty sword! Bridge the gap!
And most of all, don't quit. You'll never get anywhere if you quit.
Good luck!

"Very true," I say as I put off finishing edits. (Distant sobbing)