Singing well is all about balance, a balance that is only achieved when the muscles that produce the voice are working in a manner that is independent from those muscles that are not responsible for producing the voice.
In short, all the muscles that are not basically responsible for creating a tone should lay off and let the voice work in a free environment.
The most basic thing you should know is that your outer neck muscles, your facial muscles, your jaw and your tongue are not fundamental muscles for sound making. I like to imagine that all that exists are my air system and my vocal cords. When these two are in perfect balance everything else takes care of itself, when any of the muscles I listed tries to jump in to "help" then we are on the path to trouble.
I made this brief, simplistic and rather absurd analysis to give all of you with a million questions, a million distraction and a million worries something to focus on for the next year. If you focus on making your air and vocal cords independent from all other muscles your voice will slowly start building until you have an instrument that you can rely on.
I remember being the one wanting to know all this stuff about the voice, I was just desperately looking to learn the "techniques" that would make my voice be just as good as singers on the radio. I was incredibly distracted, I was just looking for more and more information and I wanted to be as good as someone other than me. Many of you will read this and find that this makes sense, but that will be it. It will not be until you experience what I'm talking about that you will be able to fully appreciate what I am saying. Here it goes...
What we are looking for is to make the act of singing SIMPLER. We are looking for the easiest way of producing sounds. Keep this in mind everytime you feel yourself tensing up and straining. When you are vocalizing you are looking for minimal external muscle involvement. Keep this in mind when you're making funny faces or your neck looks like it's about to blow up.
Now I want to write about why I chose "A Sense of Independece" for the subject. Basically, if you don't have a voice teacher, a mirror should be all you need until you reach a level of singing that feels easier, a level of singing that you feel you can trust and rely on. Until then, you really shouldn't have that many questions for anyone other than yourself. Just ask yourself, how can I make this easier? And go for it. You'll make mistakes, a ton of them, there isn't one trained singer who didn't make hundreds of mistakes when he/she was training, what makes you think you should be different? Be independent! Listen to your body, listen to yourself... you know what to do. Many of you are very young, but that doesn't mean you have to be dumb. You can actually choose to be smart and accept reality.
I lost motivation in writing this already, but hopefully you get something out of it.
Good luck all.