Question: What is your advice about having trouble in reaching the desired word count? I've just finished drafting my first novel but it didn't reach my goal of 100 k+ words, it was only one-third.Answer:
You have a few options.
It may be that your story is only suitable for a short story or novella. Not every story can work as a novel. That's okay, though it does limit your market. (There are literary magazines that publish novellas.) But this is something you have to decide for yourself.
However, let's assume you have a novel-worthy idea. It may be that you have run short of words because you have not fully developed your idea.
If this is the case, here are some ways to develop your story...
1. First, do not attempt to "pad." By that, I mean do not start adding scenes, subplots, or other stuff just because you need the length. Anything that is not essential to the plot will read as padding. It will make your novel boring to the reader, and a good editor will suggest you cut it anyway, which will put you back where you are now.
2. If you are not familiar with the concept of the four throughlines, this article on synopsis writing will help...
Take a look at your novel and see if you have developed all four throughlines, which include both the external plot and the main character's inner conflict and growth.
3. Sometimes, beginning writers tend to underwrite events. Take a look at each of your scenes and see if you have included all the specific details to create the emotional impact required. (Of course, over-writing can also be a problem, so be careful.)
4. Now for the big secret...
Any event in your story can be developed by changing it from a single event into a sequence of events. A sequence is an event (change) that takes place over anywhere from three to eight smaller events. Each event, including the overall sequence, follows the usual pattern of ...
setup --> complications --> crisis --> resolution
For instance, let's say you have an event such as, "a man crashes his car into a
You can write that event as one scene, perhaps as...
Setup: A man is driving down a road at night.
Complication: A song comes on the radio that reminds him of the woman he has just broken up with. He reaches into the glovebox, pulls out a flask, and starts drinking to dull the emotional pain.
Crisis: He drops his flask at the same time as a woman crosses the road in front of him. When he looks up and sees her, he is forced to swerve hard to avoid hitting her.
Resolution: the car goes off the road and hits a brick wall.
Now, let's say your story is too short. You could take that one scene and turn it into a sequence of four scenes. For example:
Scene 1: Setup. The man's girlfriend dumps him rather callously on the day he was about to propose.
Scene 2: Complication. The man decides he needs an immediate vacation, so he packs his bags. At the last second, he buys a flask of whiskey -- the first one he has bought since he swore off alcohol six years ago.
Scene 3: Crisis. This will be the accident as above.
Scene 4: Resolution. The man wakes up in hospital, except that it's a hospital that doesn't make sense. Everything is fifty years out of date and the staff keep calling him by a different name.
Okay, that example now sounds like the start of a fantasy novel. My point is that you can go through your novel and look for events that can be developed into sequences. (In fact, events within sequences can also be turned into sequences, etc.)
The advantage to this type of development is that every scene you add is an important part of a bigger event which is important to the overall story. Nothing feels like padding, because every event is important.
Please note that events don't have to be just external events. There are also internal events, such as making a decision, gaining a new understanding, having a realization, or changing one's opinion. These too can be written as single scenes or can take place over a sequence of events.
Best of luck.