Finding ideas is often the easy part. Deciding which idea to proceed with from your abundance can be the challenge.
If it was just as easy as picking your favorite, there wouldn't be a problem. But, other people make it tricky. You have a limited compacity for knowing how people will react to your work.
The problem is that you are very familiar with your own line of thought. Ideas that are surprising to you may well fall well within other people's experience.
On the other hand, sometimes a turn that seems second nature for you will blow people's minds.
Have you ever made a thing you thought was subpar, but everyone you showed it to loved it? It's hard for you to know what's good because you're too close to your own train of thought. That's why it's extremely valuable to have someone to bounce ideas off of.
Unfortunately, you may not always have that person. In these cases, it's useful to have some kind of external metric by which to judge your ideas.
A good place to start is the book Made to Stick by Chip and Dan Heath. They go over several things you can look for to find ideas that are "sticky." Things such as the simplicity of the idea, how concrete it is, and does it tell a story. They explain in detail what you're looking for and why.
Here are some other things to think about
If you're looking for your idea to be shareable, consider the degree people will identify with your idea. You want people to think "I've often thought the same thing, but they put it into words." The degree which you think people might do that can indicate how many shares you'll get.
Degree of difficulty
You only have so much time in the day. If an idea is going to use all of it, you better be pretty sure it's going to be good. On the other hand, if something is quick and easy, then it's worth a shot to see how it turns out.
Consider how difficult it may be to get this idea across. Would a child understand?
Passion is what makes things easy. It's the driving force in the things you do. If you're not passionate about an idea, even if it's good and you think people will like it, you're going to be fighting an uphill battle.
The metric by which you judge your ideas is something you have to make yourself for your purpose. All the things listed here, and even in Made to Stick, may not prove important to you and you may have your own ideas. Give it some thought, and keep exploring.