Disable app notifications by long pressing on notifications and unticking "Show notifications". Disable mobile data in Settings > Data usage to save battery life when not needing a mobile connection. Disable automatic app updates in Play Store settings to manually review app permissions and updates. Check for Android system updates by going to Settings > About phone and tapping "System updates" and "Check now". Change default apps by going to Settings > Apps, selecting the app, and tapping "Clear defaults".