Amy Hoy has a video on her site Stacking The Bricks called How do you create a product people want to buy. Here are my notes summarizing the main points of the video, which captures a "solution first" approach to coming up with product ideas.
I find the "solution first" idea very compelling because it is the opposite of how we normally imagine products get made. Most of the time people expect to come up with the idea first, build it, and then try to sell it to people. Amy advocates doing it the other way around. Start with the people first, do research to figure out what they want, make it, and then show it to them. Working backwards means you make a thing that people actually want, rather than something you imagine people might want.
According to Amy, the key to this is research.
Here are my notes summarizing the video:
Find the answer to these questions:
The solution is research.
Ask yourself "who am I serving?" This is not a big deal. It doesn't really matter. Pick a customer you like.
What does the audience need, want, and buy?
Be very very specific. Don't make something vague.
The intersection of need, want, and buy is where you should put your product.
Don't guess. Do research.
e.g. "ruby developers"
Once you have done this it should be obvious what to build.
Opportunity is missed by most people because it is dressed in overalls and looks like work.
This is the easy part.
You already know where the customer hangs out, and how they talk. Go back to their watering holes and use the same type of language they already use, to introduce the product to them.
Hope this was useful!