According to the agents and editors at this year's COFW Conference, your characters should be anchored to a time and place. Your reader may feel adrift if your character is some place that the reader cannot identify. By the same token, you do not need to describe every single detail. The reader will fill in quite a bit. Also, do not show details that your characters cannot possibly see.
Sometimes, when writing your Nano, all rules go out the door, but f you establish good writing habits, some will follow through in your other writing.
For me, punctuation is my weakness. You may have noticed that I have no "Comma Sense". I am working on this problem, as well as other areas that I am deficient in. But for NaNoWriMo ignore your inner editor. If you truly can't try to ignore it, until you have completed your word count.
Intersperse backstory throughout the novel and only put it where it is beneficial. Begin in the action, but the action does not have to be a fight scene. It can be as simple as ringing a doorbell. Sometimes, the story really begins in your second chapter, it is your job to realize this before submitting to agents/publishers.
Characters voices- give each one their own distinct voice. This is in their speech and in their internal monologue, as well as anytime you write about them. This will help eliminate the need for tags. (I am still working on this...)
To top your good idea off, your story must be well crafted and written. You can spend many revisions after November to do this.
Begin with a germ or seed of a story and make that your own. Keep your story modern, except for historicals. Make it real to the reader, even if you are writing about vampires or a futuristic story about robots. You do this by giving your characters emotions, reactions and gestures that your readers can connect to... Give your characters dimension and make them realistic.
The above is free association. I hope you can follow it. When in doubt free write and see where it takes you!