As product engineers and designers we spend our time thinking about building great products. There various techniques and methods out there.
There is an easy approach that is helping me intuitively think about this and also teach this. It is, to start thinking of use cases as moments in the life of a user as he uses your application\product. Now try to figuring out happy or sad moments he has.
Once you have this you can optimize the UX to create more happy moments reduce those not so happy moments.