Can you be more specific? Creating a mockup/wireframe/protype with online tools like Invision or Balsamiq is a good start, and then putting it in front of people to gather feedback. You can also go straight for the MVP - build the smallest, cheapest usable version of your product and see if that fills a need and gathers good feedback. If so, you have encouragement to go further. More tips here: https://www.productschool.com/blog/experience/product-manage...