Apple makes it easy to take screen share with iOS and macOS with new devices

Here is a procedure on how to screen share with iOS, iPhone, iPad, iPods and macOS to help friends and family with new devices without any third-party software.

Mac to Mac Screen Sharing

Providing support to others can be even smoother when you can take control of their device. When you do Mac to Mac screen sharing this is an option, you can also share your screen instead of seeing theirs. To do this, make sure the ‘Screen Sharing’ box is checked in System Preferences → Sharing. Also, if the Apple ID they use for iCloud and Messages on the Mac is different, you’ll need to have both emails on their contact card.

Here are two ways to start screen sharing:

Method 1

1. Do a Spotlight search for ‘Screen Sharing’ and launch it.
2. You’ll then see a dialog box with the option to enter the Apple ID of the person you’d like to screen share with.
3. On the receiving end, they’ll see this invitation.
4. Make sure they select ‘Control My Screen.’ The alternate way to start screen sharing is through Messages on macOS.
5. Click ‘Details’ in the top right corner of the message of the person you’d like to screen share with and select ‘Invite to share my screen’ or ‘Ask to share the screen.’
6. They will receive the same accept or decline notification as above and also accept your ability to control their screen.
7. Once you are connected a FaceTime voice call will also automatically initiate and you’ll see everything on their screen.

Method 2

1.  Open QuickTime Player and start a screen recording (File → New Screen Recording) so they can revisit the guidance anytime they want.
2. When you’re ready to end the session, you can click ‘Screen Sharing’ next to the  in the menu bar and select ‘Quit Screen Sharing.’

Screen Share iOS Devices Using Macs

This is a helpful modified use of a developer feature that Apple has built into QuickTime Player that came along with Yosemite. When you use the Screen Sharing Mac app with this screen casting feature option you can see everything happening on an iOS device as long as both parties have Macs.

Here is the procedure:

1. Start a screen sharing session. Have the person you’re helping plug in their iOS device via USB cable to the Mac that they are screen sharing with. 
2. Launch QuickTime Player and click ‘File’ and ‘New Movie Recording.’
3. Once the movie window opens, select the drop down arrow next to the record icon and click the iOS device you’d like to see, then click record.
4. After you’ve solved all their issues, you can even help them save the footage so they can review it later and remember the solution again in the future.

Source: 9to5Mac