The best way to find Microsoft opportunities is to look at a large software that you're very familiar with and make a list of 10 things you would improve to enhance the experience. Out of this 10 things take the top three and talk to other customers who use that same software and see if they're having those issues too.
This is how you validate your idea with the market. If you fail to validate your idea first you're going to be in for a lot of trouble later down the road which is why I suggest doing this first.
After your idea is validated, you'll next one too create the minimum version of the software project and try to get a cash flow positive as soon as possible.
That's the route I took when I started Trend Watchers and it worked really well. I attached a few images below that displays my progress from MVP to what it is today.