After working with ideas over the past decade, I've learned that, in the beginning, there is no such thing as a good idea.
Ideas are inherently worthless until you share them with others.
Each time you ask for feedback on an idea, it grows a little in value. Not only will you be able to refine it, you'll also win over one more ambassador for your idea.
That's why instead of letting your idea die in a notebook, you should give it a fighting chance by sharing it with others who might find it useful.
Don't worry. Like most things, it gets easier with practice.