Very good discussion!

When I was learning, my big problem was landings. I couldn't land smoothly.

I got bad advice initially: I was told to chop the throttle to idle on final and let it "glide" in. The plane lost too much altitude to even make the field, and I started feeding in up elevator to (or attempt to) preserve altitude. Bad habit to develop! I'd either lose airspeed and stall at 4-8" or come in too hot and bounce. Once I was told (or I figured out) to modulate the throttle to maintain altitude/control glide path and use the elevator for pitch control, my landings improved.

Wade, "unstable" and Horrace have it right.

On thing I found helpful was to go around and make landing approaches. Each pass, decrease the throttle a bit more each time until you get a good glide slope. When you are close you can modulate the throttle up or down to gain or lose altitude.

Practice, practice, practice.

Bad landing habits tend to snowball. If you have a bad landing, you get nervous the next time and have a badder landing, and so on downhill.

Oddly, my landings started improving when I started flying sailplanes. In that case, the throttle stick operates the spoilers, which are the glide path control. But flying "on the wing", you get very attuned to what the elevator/pitch control does to airspeed and you use the elevator sparingly.