In my hand ready for immediate action for the most part.
How do I pull that off while carrying it concealed you ask?
Glad you asked cuz I got an answer fer ya.
I wear vests. I have several and exactly where it goes and how it's used depends on the vest. My cool weather vest is the very best there is. It's basically made like a hunting vest with a game pouch that is front loading and the pouch of it extends all the way to the zipper area of the vest. I just tuck the S&W 638 in that on the right side. Then I can walk across the parking lots with my hands in those pockets like I'm trying to keep them warm and at the same time have the revolver in hand ready for immediate action. Note that it is the 638 meaning light weight SS and with the concealed hammer that can still be accessed for single action fire under extra accuracy is needed. It can be fired from inside a pocket without worry of the concealed hammer catching on the clothing.
The other vest I most often wear is a much lighter weight camo vest also with game pouch but it can't be used as the above vest. With it I have to put the revolver in the right hand front pocket which has a snap to keep it closed. Most often when walking in a parking lot the snap will be unfastened and my hand in the pocket on the revolver. When I get to the store or to my vehicle depending on which direction I am traveling I snap it and go about my business.
In each case I have the gun actually in hand and ready to be deployed instantly even without having to remove my hand from the pocket if there is that much rush. This method might not work as well tho with a 36 as the hammer might catch on the vest material so you'd likely need to remove it before firing to be sure of having a second shot if needed.
I'm tried holsters and have several types available but have never yet found a more secretive carry method nor one that allows the revolver to be deployed as quickly and if the SHTF and you need to use it you need to use it as quickly and effectively as you can.
In really cold areas a large coat pocket can be used same way rather than the vest pocket.