Writers, like everybody else, dislike uncertainty. When we solve a problem we get a nice rush of chemicals to the brain.
The downside of that is that it tends to make us settle for the first good idea we have. Going past it makes it seem like it's not good enough and that returns us to that unpleasant state of doubt.
This is the origin of the statement that "good is the enemy of great."
In other words, if we settle for the good idea we won't keep going long enough to find the great one.
Sometimes the first good idea does end up being the best one but often it's not. This is true whether you're trying to decide on the best title for your book, the best name for your protagonist, the best plot twist for your mystery.
One way to ease into the habit of keeping looking after you come up with an acceptable solution is to allocate a set period of time to considering further alternatives. This could be just five minutes or several sessions of fifteen or twenty minutes, depending on the importance of the problem.
As in any brainstorming session, generate as many ideas as you can without judging. Then, in a separate session, evaluate them and choose the one that works (or decide you need further brainstorming).
If you do this regularly you may find that your writing isn't just good but great.
(For some good and some great ideas on how to be more creative, get my book "Creativity Now!", published by Pearson and available from Amazon and other book sellers.)