Wouldn't it be great if there was someone who'd do the finishing for all of us? When I began writing I was brilliant at beginnings and had deskfuls of Chapter Ones. I was useless at the Finishing bit though. (I wasn't much good at the middle, either, to be honest but that's another story.)
Writing short stories helped me. They were, by definition, short and got me into the habit of finishing. As I learned about writing and wrote more short stories, I got better about finishing them. Gradually I realised any ending was better than none, because then you could DO something with them - send out to magazines or competitions, for example.
Fast forward a couple of years and writing the first draft of my first novel. I did it in one immense push taking 10 weeks - the school holidays were coming up and I knew I wouldn't be able to sustain writing AND childcare. I didn't know what was going to be the 'right' ending. Were my characters going to split up or stay together? I flipped a coin and gave it a 'they stay together' ending. Later I rewrote and gave it a 'they split up' ending. Even later I rewrote again and gave it a completely different ending.
That turned out to be the 'right' ending for the story, but for the first draft it really didn't matter what ending I chose so long as it was there. I see many students who can write really well but because they never finish any work they can't move on and do anything with it. People sometimes ask me if I think their work will get published, and I say, 'Finish it first, then ask.'
Unlike Inventor Tom we have to learn to be Starter Finishers because no one will do it for us. I used short stories to develop my Finishing habit. Any other suggestions for getting to the point where you can write "The End"?