Most of my students had trouble with Power off 180s, the biggest issue was that they always doubted themselves when it was time to put gear and flaps. They waited a second or two... which always caused them to be high on the approach. Fly with a CFI and find out what the profile is for the aircraft that you fly. Then fly the profile every single time and don't hesitate to drop gear and flaps when you need to.

You can also try flying on the back side of the power curve... drop flaps way too early that way you'll come up 100-200 feet short of the runway, requiring you to add full power and do a go around, then try it again.