There are a bunch of threads about this, which would probably be a great resource, but my preferred method is to hover above head height, place my flat palm face up a few feet below and then left stick down. The Mavic will pause about two feet above your hand, as it thinks it's the ground, then lower onto your palm. Keep holding the left stick down the entire time, and the motors will shut off just after it lands on your palm.
I will say this: hand catching, imo, should only be used when you don't have a flat, clean, hard surface to land on. Which does happen quite a bit. But, when at all possible, use the ground or a landing pad. I was hand catching in a bit of a breeze the other day and she shifted just a bit left as she touched down on my palm. Instinctually, my fingers closed up over the sides...because of the lean mostly, I buzzed the end of my thumb. No real damage done, but only because I was very lucky.
To be fair to yourself, you should google something like 'hand catching drone accidents' and look at the pics. Gruesome. Like I said, it can be done safely, and I do it often because of where I fly, by you owe it to yourself to have a healthy respect for it and what it can do if it goes just a little wrong. Pictures tell a thousand words...respect the props.
