Actually, good or bad ideas for writing don't exist - only the novels that the writing ideas become can be judged in those terms.
And you shouldn't worry about a lack of originality making your ideas bad ones, either. Why? Because the odds are that they won't be original, at least not when you strip them down to the bare essentials.
It is what you do with your ideas - the way that you develop them, the spin that you put on them - that will make them your own.
But the bare bones of the original writing ideas? Trust me, somebody somewhere will have got there before you. Or as Ralph Waldo Emerson put it...
However, there are such things as good or bad writing ideas for you...
That last point is important. Living with promising ideas for a couple of days, and seeing if they do indeed keep you awake at night, is like taking your ideas out for a road-test. Will they pass or fail?
You will know they have passed if they have you buzzing with excitement.
"The first person you should think of pleasing, in writing a book, is yourself."
- Patricia Highsmith
A novel idea is exciting when the creative possibilities contained within it seem limitless, and the novel you can envisage at the end of it appears to be truly great.
(The fact that most writers' novels, by their own admission, rarely turn out to be half as great as they seemed when they first imagined them is another story!)
One of the consequences of this buzz of excitement surrounding your novel idea is that it will make your mind reel with more ideas for all the things the novel could contain...
Be sure to make a note of all these fleeting ideas, because they might not visit you again.
Write them down on the backs of envelopes, restaurant napkins - whatever is to hand. And then later, at your desk, you can incorporate them into Story's "Master Plan".
Realizing you have found the perfect idea and that you can't wait to get started on it is a heady experience.
If you find ideas for writing which are merely okay, ones which tick all the boxes but don't have you buzzing, keep searching for better ideas, ones you really want to write.
I promise you, you will know the right idea when you find it.
You are a unique human being. Nobody sees or thinks or feels or does anything quite the way that you do. And a novel is perhaps your best chance of showing your fellow humans what this world looks like through your eyes.
Why is it important to do that?
Because if you try to fake it in any way, it will show up in your fiction. So if your ideas for writing don't truly reflect who you are as a person and what you are all about, ditch them and keep searching for some ideas that do.
You'll know you have settled on the right one when you can't keep from smiling!
Next Up: If you still aren't 100% sure of the idea you have come up with, try Taking the Idea Out For a Road-Test...