Tools can harm or heal. What matters is whether they are used intelligently or indiscriminately. This last word is important. Beautiful singing entails a high level of discrimination. But all too often the student isn't ready to observe what they are doing and hearing even if they know something isn't quite right. Do they listen to their recorded lessons or work with a mirror? Nope. They want to be 'cured' of their vocal ills without lifting a finger, opening their ears or seeing what is before their eyes. Fix me! They cry to the vocal pedagogue. Give me the one tool, the secret technique given only to a few that will make everything right! But please don't ask me to observe myself! Just give me what I want!
Does the master carpenter give his apprentice a tool and tell him to start cutting away without thought to the what, where and how of what he is doing? Is one tool sufficient for every design? No. That is not the way of the master craftsman in any of the Arts, be they fine or otherwise.
There are no quick answers or cures in learning to sing, which is not to say that it takes forever or is an arduous practice (if it is then something is wrong). But a little knowledge can be a dangerous thing. The vocal techniques on these pages need to be applied with great care. They also require a living model in order to be fully understood.
Sometimes the best tool is no tool at all.