I remember watching a cartoon based on Greek mythology when I was a child.
King Midas is walking on the street and sees a hungry homeless guy, so he picks up a small rock and makes a fist around it. A bright light shines out of his hand and that rock turns into a solid gold. He gives it to that guy so he can buy some food for his family. It was and still one of the most magical things I have ever seen. Since then, in my imagination, if I want to turn a small thing into another thing or if I want to vanish something, I would make a fist around it.
I told that story so you can understand why I think making a fist and opening it is the most magical action.
Whenever I imagine I am making a coin disappear in a most magical way, I imagine having a coin in my palm and I close my fist. Wait for a few seconds and the coin is gone when I open my hand. There should be no fast movements nor misdirection or does not require any technique. At least in spectator's eyes. Looks kind of like this.
If I choose to use false transfers or any other method to achieve a vanishing effect, I do not close my hand because I am going to make a coin disappear. I close my hand because the coin is already gone but I have to pretend that coin is still there and "make it disappear".
There is usually one problem people don’t usually notice. They close their fist for TOO long and that looks extremely awkward. At least to me. The only reason anyone makes a fist around something is he/she is afraid of dropping stuff from their hand. However, closely guarding a single coin is not a normal person would do. Oh, if you toss a coin upward/sideway and catch it, then the catching hand has a proper reason for closing fist though.
If I want to use a false transfer and still look good, I have to manage timings of movements perfectly and use a little bit of misdirection/direction so I can be less guilty about not being able to do real magic.
Hmmmmm... How about tossing a coin into the left hand so it has a proper reason to close fist and without any hesitation start to vanish that coin...