Stephen D wrote:'It's in the wrist'
Once you apply the direct heat to the top and work the flame around the terrine/ ramiken, you will get to a point at which the sugar will begin to liquify and turn dark brown in places. Rotate the terrine while applying occasional heat to keep the sugar in motion. Once the whole top has a decent color, stop. It will set nicely for you.
What Stephen said, and...
The farther you keep the flame away from the sugar, the better.
Sugar will begin to liquefy from a flame (obviously), but the farther the flame the slower the process and the more control you have.
Patience.
Ambient heat will warm the sugar slowly, and as it liquefies, it won't immediately go to the caramel stage (like if you have the torch close).
This enables you to control the sugar, and not end up with patches that are turning black because they are burning... while you still have patches of raw crystalline sugar.
Another trick is to do this, but only cook the sugar until it liquefies but doesn't caramelize.
Sprinkle another layer of sugar, and repeat.
You can do this as many times as you want, but 3 times should be ample.
And you now have an extra thick layer of evenly caramelized sugar "crust"
Also:
Make the brulees from scratch. Those powdered mixes they sell at places like Williams-Sonoma and Bed, Bath & Beyond are garbage.
Brullees really aren't too hard to make from scratch as long as you remember the old adage: "low and slow".
Rotate the pan, have a deep water bath to cook them in, and they're done when they don't look wet or still liquid, and have a nice jiggle when you shake them (think of the old Bill Cosby Jello commercials).
And just because one is done, doesn't mean the others are.
The pan and your oven will not evenly disperse heat, thus depending on where in the pan and oven your ramekins are, they'll cook at entirely different rates.
Remove them as they finish, and put the rest back in the oven.
Patience, remember?
Once your brullees are done, allow them to rest at room temp until cool, then put them in the refrigerator for at least 4 hours until well set.
After all, this is a dense set-custard we're working with here.
Then torch away to your heart's content.
Side note:
As a professional, i swear by Bernzomatic MAPP gas (in the yellow can), over their standard gas (in the blue can) - it burns hotter and at a higher rate of fuel (bigger, stronger flame), and is hands down 100% more versatile (and faster) in a professional setting.
