Revision can be a daunting task if you’ve completed the first draft of your manuscript, but there are ways to make it more manageable. Remember: You don’t have to do everything all at once.
First, put your draft aside for a few weeks or months. Taking a break helps give you some distance so that you can approach it with a fresh eye. If you get new ideas, write them down in a separate file. Try not to tinker with the main manuscript at all.
Second, consider taking this time to send your draft out to a trusted circle of writers/friends with notes about the kinds of feedback you want — and it may differ from person to person. One person may have an eye for line editing, while another is great at critiquing character or plot. It will take time to collect their responses, and hopefully their feedback will help you focus on certain trouble spots as you revise, especially if it cites recurring issues. (Consider a small gift, homemade treat or offering a reciprocal edit to thank them for their time.)
When you are finally ready to return to the manuscript, make a copy of your master draft. Call this Revision 1 (or another label that you find helpful to organize drafts so that you can track changes). Choose one aspect of the manuscript to revise on this draft — grammar, dialogue, setting, transitions, etc. Make changes and then copy this draft. Call the next draft Revision 2 and choose another single specific aspect of the manuscript to revise. And so on, and so on. You may find it helpful and even necessary to go through this process more than once. By focusing on a single task at a time, you can improve your manuscript in an organized way that is both highly do-able and efficient.