Easier and/or better
As you work on your vocal technique, apply this rule ruthlessly:
The exercise you are doing needs to either make you:
- sound better, without being more difficult
- sing more easily, without sounding worse
Sometimes, you will get both #1 and #2 together, but not always! If you have been doing an exercise or a technique for a long time and neither #1 nor #2 is happening, drop it.