Making a back up via your iPad or iPhone:

1 – Connect your device to Wi-Fi.

2 – Plug your device into a power source.

3 – Go to Settings.

4 – Select your account at the top of the settings menu. (see below image)

5 – Select “This iPad” or “This iPhone”. (see below image)

6 – Select iCloud Backup. (see below image)

7 – Select Back Up Now. (see below image)

Making a back up via your computer (iTunes):

1 – Plug your iPad/iPhone into your Mac or Windows PC.

2 – Launch iTunes.

3 – Select the iPad/iPhone icon in the menu bar when it appears.

4 – Click on Back Up Now. (The backup can be encrypted for extra security.)

Wiping your iPad/iPhone:

Once you have backed up your data safely, it’s very important to wipe the data from the iPad/iPhone you’re selling/disposing of.

1 – Launch the Settings app from the Home screen.

2 – Select General.

3 – Select Reset at the bottom of the General menu. (see below image)

4 – Select Erase All Content and Settings. (see below image)

5 – Enter your Passcode. (see below image)

6 – Finally, click Erase to confirm. (see below image)

  

7 – To turn off Activate Lock and remove the device from Find my iPad/iPhone, you will need to enter your Apple ID password. Once the wipe is done, if you change your mind, you would need to restore your account and settings with an iCloud or iTunes backup. (see below image)