Some ideas...
Find a long runway and practice touch and goes, but you set up the landing so the student just concentrates on that.
The pattern has to be very good, to get a good landing, so make sure your students are flying through the "gates" properly.
Sometimes, it helps to back track. Do the landing yourself while the student follows you on the controls.
Operate the throttle while student lands.
Make sure that as the nose comes over the numbers, the student is looking at the far end of the runwy, have them focus on something as they round out and flare.
Have them pull up the nose incrementally in the flare. You can use a grease pencil to make a line on the windshield to show the proper attitudes. Fly the airplane down a long runway in the landing attitude while your student gets the sight picture. You control the throttle, have them touch down and hold the attitude longer for it to sink in.
I once had a navy helo pilot who could fly beautifully, until roundout, then he pushed the nose down. I had 0 experience in helicopters and sought out the advice of a DE. It was a negative transfer problem; you are supposed to land a helo that way. So I just rode the controls with him, and kept my fingers behind the yoke. Everytime he pushed forward, I prevented it and reminded him not to do it. In a few hrs, he broke the habit. Don't be hesitant to ask the more experienced for help, you are doing yourself and the student a disservice, if you don't.