For many authors, this step is the toughest. You need to let the first draft rest. Preferably for as long as a month. That might seem like forever, and you might think you'll lose valuable momentum on your novel, but trust me, this is important downtime away from the book. The reason you want to wait is so when you do start tearing into that first draft, the words and story will seem fresh to you. This makes it much easier to catch mistakes and to be open to changes that need to be make in order to create a better story.
What can you do in this downtime? I like to work on other projects, such as short stories or thinking up new novel ideas. I also occasionally take time off from writing anything and simply read more than normal. It doesn't matter what you do, as long as you take your mind off your first draft. You'll be worrying enough about it in the coming months, so enjoy this time now.
That's it for this week. Simple advice, but sometimes difficult to achieve. When the new year gets rolling, I'll get into my actual revision process. Until then, keep writing and/or reading.