I would like to start by looking at the last point, Android without Google services. In this case, there are positive and negative sides to which we should pay attention. By using clean Android you give up all Google services, and that includes Gmail, YouTube, Earth&Maps, Google Play and many other things. The question then is what apps to use on your smartphone, where to get them from and how to be sure of their credibility? Google Play Store is not perfect, but still provides a somewhat solid level of security. Should I mention that you need custom ROM for free Android, and the knowledge to install it...

Using PIN, keep device up to date, and turn off all unnecessary spy features are smart tips. For those who would like to avoid Android completely, there are some alternatives in the form of Linux smartphones.