position the tip of the BLUE flame at the back of the fitting, shoulder, where i show the big arrow, move the torch around the fitting,
You don't need a really super hot flame to do this. I see to many guys hold the flame on the bottom and wait for the other side to get hot enough to melt the solder. Larger fittings require a little more technique.
I like to give an example of cooking up some eggs. medium flame, Not high flame. or you burn them.