How to safely shut down or force shut down Apple devices

Apple iPhone 8 Apple iPhone 8
Apple iPhone Apple iPhone
Apple iPhone 3G Apple iPhone 3G
Apple iPhone 3GS Apple iPhone 3GS
Apple iPad Wi-Fi Apple iPad Wi-Fi
Apple iPad Wi-Fi + 3G Apple iPad Wi-Fi + 3G
Apple iPhone 4 CDMA Apple iPhone 4 CDMA
Apple iPhone 4 Apple iPhone 4
Apple iPad 2 CDMA Apple iPad 2 CDMA
Apple iPad 2 Wi-Fi Apple iPad 2 Wi-Fi
Apple iPad 2 Wi-Fi + 3G Apple iPad 2 Wi-Fi + 3G
Apple iPhone 4s Apple iPhone 4s
Apple iPad 3 Wi-Fi Apple iPad 3 Wi-Fi
Apple iPad 3 Wi-Fi + Cellular Apple iPad 3 Wi-Fi + Cellular
Apple iPhone 5 Apple iPhone 5
Apple iPad 4 Wi-Fi + Cellular Apple iPad 4 Wi-Fi + Cellular
Apple iPad 4 Wi-Fi Apple iPad 4 Wi-Fi
Apple iPad mini Wi-Fi + Cellular Apple iPad mini Wi-Fi + Cellular
Apple iPad mini Wi-Fi Apple iPad mini Wi-Fi
Apple iPhone 5c Apple iPhone 5c