When everything is going right, stories can get boring. That’s why we have troubles along the way to spice things up. But adding plot twists isn’t quite that simple.
If you’re trying to find ways to make your story more interesting, look at the pivotal decisions and moments throughout the novel. If you have your characters succeeding at one point, what if they failed? If one character always remains loyal, what if they became a turn-heel? These “what if” questions allow you to explore other directions for your story to go and possible obstacles to make things more interesting.
It’s not enough to just add twists, however. You need to also include some foreshadowing. Good twists don’t come out of the blue; they appear to, but when one looks back at the rest of the work, one will find that the ‘twist’ was actually foretold all along. GRRM does this beautifully in the A Song of Ice and Fire series, hinting at the details that will lead to major character deaths and shocking plot points. Not only does this make your novel a fun reread, it also shows the logical progression from point A to point B.
Proper twists aren’t complete without foreshadowing, and if you can pull it off, your readers will be delighted (or hating your guts for putting them through so much emotional pain).