I hate it when I finish writing a novel, but I also love it :)
I love it because I finished it, and hate it because I'm done writing it. Do you understand? I get butterflies in my stomach when I'm finished with a novel, but then I'm kinda sad that the novel is over. The first book I wrote was part of a trilogy, so when I finished writing the first and second books it wasn't really over. So I didn't really get that feeling. When I finished the first novel I was totally excited that I had actually wrote a book. And then the same day started writing its sequel.
But I just finished a one shot book and I was a little upset that it was over because I really enjoyed writing it. (It's copyrighted now and I'm trying to get it published). And I'm almost finished with another one shot novel (my 5th book) and I'm kinda sad about it too. This one will most likely be self-publishing, so I'll update when it's posted or whatever, but it won't be until late next year or so.
Anyway, since I'm almost finished writing my 5th novel I decided to blog about the ending of your novel. N. O. V. E. L. As in fiction, not nonfiction.
When you are finishing up writing a book that is part of a series you don't want to hurry up and write everything into the last few chapters. You want to leave things for the next book.
You also want to leave the final chapter, the final page, in a cliff hanger. Something that will leave the reader wanting more that moment and hate the fact that they will have to wait a whole year, or a few months, to get its sequel.
When you end a one shot book you want to make sure you went over everything in that book. That everything that that character was experiencing was conveyed clearly so the reader will understand. You also want to make sure you got every secret out. For example, you wrote a novel about a girl that has powers, but she doesn't know what she is. If you are writing a one shot you want to make sure that your character finds out what she is before the book ends.
If you want some examples you should read the first book in a series, then once you've finished that read a one shot. That way you get a good idea of what you should do, and maybe you'll get a great idea how to end your book :)