single identity across multiple devices

I have a Mac Mini, Macbook Air, iPad mini 2 and 6s Plus. The problem is syncing the phone. i take the laptop on the road a lot and then come home to the mini. I am afraid to hook my phone back up to my mini for fear of losing the settings and customizations i have made and having to start over. How can i manage syncing the phone with both the laptop and the mini and not lose stuff?