I'm not sure what the 'technically correct' approach is, but mating these m42 lenses to the Alpha body means they only work in manual mode, so I set the desired aperture on the preset ring*, open up the aperture wide, focus, check the exposure meter on the camera, stop down to the preset aperture, recheck the metering and if it's under or over I will adjust the shutter speed to compensate until the metering is centred at 0 or just over, and fire.
It makes photos on the walk a bit interesting as with the constantly changing metering (clouds etc) and focusing you have to be quick without missing a step. I've lost count of how many pics I've messed up because I've not refocused after the last metering check
*the early 44M's like mine have a switch on the lens; flick the switch one way it opens aperture fully to allow focusing, flick it the other way it will stop down to your preselected f-stop for shooting.
** the Jupiter has two aperture rings, the first adjustable one sets the maximum f-stop you can hit by turning the second ring (which actually opens or closes the aperture).
*** at ISO 100, I set my default shutter speed to 1/focal length to give me a starting point