Have you ever released a bowling ball down the lane towards the pins and "coached" it as it rolled, begging it to go a little farther to the left? All of us humans engage in such obviously pointless, semi-superstitious behavior from time to time, hoping in vain that, if we wish hard enough, we can alter the physics of everyday objects.
Despite our wacky behavior at the bowling alley, in reality we all realize that, once the ball leaves our hands, we have no more control over it.
In the same way, we have no more control over the quality of a sung tone once our vocal cords have begun to vibrate. After that point, all of our attempts at "placing" the tone or otherwise enhancing it fall into the category of superstition.
The only point at which we have a real chance of affecting the quality of our sound is at the moment of its inception. For this reason, our state of mind in the moment just before we start to sing is of utmost importance. This is the only time in which what we do, or more importantly, what we DON'T do, has a chance to benefit our tone.
The proper sequence is therefore: 1) think, 2) spontaneously release the tone. What you get depends on the conditions that were in place at the moment your vocal cords began to vibrate.
Incidentally, if you want to bowl a strike, you'd better make sure the conditions in place at the moment you release the ball are correct. After you let go of it, all you can do is watch it roll inexorably to where you aimed it.