A junior of mine was always scared to fall from koshinage...
She screamed everytime I picked her up. Then my sensei came and said, "This is the only way she'll learn." She's still paying attention and suddenly he picked her up and just throw her, she screamed but landed safely. She got up and casually said, "Oh, I'm OK."
After that, I just kept throwing her immediately without suspending her midway. She screamed everytime but landed safely each time. She understands ukemi very well but lack confidence. After a few koshinage, she stopped screaming, and we all clapped.
I don't recommend this way to inexperienced practitioners. The way my sensei and I did the koshinage, although done swiftly and directly, took a lot of care for the uke safety. We made sure she'll land safely no matter what. We all see the need to build her confidence.
The way the I did the koshinage was that I completely turned her around until she was facing up then I let her go. This way her head completely cleared the ground. I wasn't exactly paying attention on how my sensei did it though.