We are currently working Next-Gen projects and am struggling on how to set up JIRA so that we can track time. In my last org we were able to set points and time to stories, and then use sub tasks to track work and log time against the sub-task, which would reduce the amount of time on the story. I can see in the next gen projects where you can log time and then time remaining (which is a bit manual). Any direction would be fantastic 
Thank you!
Dot