What are the #1 problems you're trying to solving? Write out 1-5 problems, each on their own line.
Don't try to solve too many problems at once. Focus on the #1 problems. Solve that #1 problem very well.
Google started out with a simple search engine with very little features (Their MVP - Minimum Viable Product). The point here is that they want to solve the problem of pages not being properly index. They focused on solving that #1 problem and made that solution superior to all other existing alternatives.
Example (for StartitUp):
It's very hard for an aspring entrepreneurs to find the best practices to follow when starting up a business.
Startup knowledge is being outdated too quickly. There is no place that consolidates all the best knowledge.
Startup knowledge are often theories - not immediately applicable for many people
Action items are not organized chronologically, so it's hard to know when you should do what.