"It's the same kind of mental motion as pushing more weakly with your hand, or speaking more softly with your voice.  Relax.  Be less tense, and put less of your tension into the magic."

"But also, it isn't actually bad that you were using more power than I did; it was a failure to follow instructions but not dangerous in itself.  So next time, you'll try to make falash and then you'll try to make more or less falash, and it won't be a problem if you overshoot."

"For a sorcerer, it should be the same kind of mental motion as pushing more weakly with your hand, or speaking more softly with your voice.  Relax.  Be less tense, and put less of your tension into the magic."

"But also, it isn't actually bad that you were using more power than I did; it was a failure to follow instructions but not dangerous in itself.  So next time, you'll try to make falash and then you'll try to make more or less falash, and it won't be a problem if you overshoot."