I have a cutting grown Brugmansia...'Peaches n' Cream.' It's one year old in a large pot (15" x 14"). It looks healthy. I water every day, and fertilize often (Miracle Grow). Why doesn't it bloom? It's about 2 ft. tall and has many healthy leaves.
You may be adding to much Nitrogen which will make lush green plants and no flowers.
Adding Phosphorous will help. Bone Meal is a way to do this.
Here are some links for you.