I teach all my dogs "watch me." Next to come and leave it, I have found it invaluable. Okay let me explain that with Rotties and Chows, eye contact should be taught from the moment they can focus to get over the concept that it is a challenge (G-d I love how basenjis gaze into your eyes!) and teaching them to lock eyes on you is sometimes a life saver… gives their minds a moment to disengage from whatever it is they are considering so they can hear the next command, lol.
I do it with food at first. I know some use toys but food pops in mouth, gone, ready for next.
Here seems to be a fairly basic explanation because I am waiting on dinner and too lazy to type:
I also recommend Mary's links. Btw, her long haired rottie is from my line. We nearly stroked, but it happens. So having her in a perfect pet home like Mary's was a blessing.