I generally do high level domain modeling first to get some ideas of the overall picture. I then tackle each components separately based on their complexity.

I generally do high level domain modeling first to get some ideas of the overall picture. I then tackle each components separately based on their complexity. Like ER for data, sequence for communication, class for structure. Overall, nothing too details since it's most likely will get change at some points but it is a good starting place. If you are interested take a look at an app I made for Android and IOS called DrawExpress. I made it to help me with drawing UML and ER quickly. It based mostly on gestures for effeciency although may take time to get use to that style. You can check out the free lite version first https://play.google.com/store/apps/details?id=com.drawexpress.lite https://play.google.com/store/apps/details?id=com.drawexpres... https://itunes.apple.com/us/app/drawexpress-diagram-lite/id687459234?ls=1&mt=8 https://itunes.apple.com/us/app/drawexpress-diagram-lite/id6...