A good idea often comes with two characteristics as following:
When you try to do a side project, start with the problem and make a product that is time-saving and beneficial. In this way, it's hard to fail.
It's a common reason for the dead projects that the author is no longer motivated. You can be charged up by solving your own problem.
The following questions will provide you with deeper understanding of your project and help you test your idea. It's never too late to begin after answering the questions below.
Who're the target users of the project?
What's the cause of users' dissatisfaction? If they see your project, will they say: "Oh, thank you. I wish this had appeared sooner. "?
What contributions do you make to them with your project?
Write an article from the perspective of an imagined user to describe the project and how much help it brings to users.
Consider a title for your blog. Is the idea new enough for the target users to click on it and share it even after days of using?
What are your target users' criteria for measuring its value? Can your project stand on these criteria? (Can your product do something that others can't? )
The questions above refer to Startup idea checklist.
My suggestion is to maintain a list of ideas, and record the problems and ideas that you usually think of. Good ideas and good pain points will stimulate you repeatedly and you will finally manage to come up with a good idea.
There are always countless numbers of brains trying to find problems to solve, so your idea is rarely that unique. You can refer to existing solutions and thinking over why they worked, or why they didn't, and why others will choose your product instead.
I usually use the following tools to find competing products: