I did these settings and now I am quite happy with my S3 phone:
- Set network mode to GSM only - basically one mode as opposed to Auto (Settings -> More Settings -> Mobile Networks -> Network Mode). Will get rid of "Refreshing SIM data" message.
- Turn off WiFi power saving mode thru secret code (Samsung Galaxy S3 WiFi Problem Fix | Galaxy S3 Reviews
). No more annoying Wifi connection msgs.
- Turn off Wifi notifications (Settings -> Wifi -> Advanced)
- Keep Wifi On during sleep (Settings -> Wifi -> Advanced)
- Disable check for internet service (Settings -> Wifi -> Advanced)
- Limit Background processes -> Set it to standard limit (Settings -> Developer options)
- Disable Animation and Transition effects (Settings -> Developer options)
- Turn off Power saving mode
- Set brightness as per your general preference as opposed to leaving it on max or close to max at all times.
- Set Screen Mode to Standard (from Settings->Display menu)
- Start S-Voice -> Bring up settings -> Disable Launch S-Voice by double-pressing Home key
- Remove weather, location, temperature widgets from your home screen. Other than clock any widget that must work in the background to refresh/fetch/compute information during display of Home screen will cause a slight delay in bringing up the Home screen.
- Create direct-call and direct-msg widgets for people you connect with daily.
- Make sure you've the right shortcuts on your home screen. Reaching an application by browsing thru pages drains the battery.
- Put big widgets like Calendar, Planner, S-Memo, etc., on separate windows. This helps you directly jump to them.
- Set Owner information. If you lose your phone it's easy for anybody to see your name and number
- Set Phone tracking on the Phone and Samsung website. You can lock, disable, track, wipe-data, etc., on your phone remotely from your PC. Awesome feature!!!!
- Set driving mode configuration carefully. And don't forget to enable it while driving. It will save your life and others on the road. This feature works really well.
- Know that the phone has a torch (assistive light). It's very good. If you could be in places where you might need it on demand (like camping or crawl space). Create a shortcut and place it accordingly.
- Enable voice-assist for Camera (and other features as needed). For example: When you say "shoot", the shutter is triggered. No need to press the shutter button and cause the camera to shake. Also try out the 2-second timer. It gives you just enough time to hold the camera steady.
- Turn off Blue-tooth, Wifi, GPS and Mobile data when not required for a long period of time.
- Set a password to ensure data protection.
Please try these and provide feedback for further learning. Thanks.