Gotta say that coin on the front sight is a challenge!I had a couple of old BB guns I never used, so in March I bought a bullet trap rated for up to .22LR and shoot at home. The triggers are crappier than any trigger on any firearm I own. One uses CO2 to reciprocate a slide while the other doesn't. Neither is as accurate as any pistol I own. Still decent practice for cheap and in my mind, if you can shoot an inaccurate gun with a shitty trigger well, you should be able to shoot a better one better.
For dry fire with handguns I sometimes try the coin trick of balancing a coin on the front sight and pulling the trigger through without the coin falling off the sight. For the most part I just slow fire while focusing on fundamentals slowly and one at a time. Sometimes I'll dryfire practice drawing and getting off a shot in front of a mirror. I'll do the same with ARs from the low ready.
With my rifles, I'll lay prone and snap in on a penny or dime. I'll try to get honed in and zen and time pressing the trigger at my natural respiratory pause at the same point in my heartbeat. Start totally relaxed, then raise my heart rate a little, then a little more with pushups, jumping jacks, etc. Main focus here is to have the crosshairs not move at all and to get the hammer to drop at the same point of your breath and heart beat.
I used to dry fire with my shotguns by swinging them across the corner where my wall and ceiling meet and pull the trigger when my sight hits the corner. I don't shoot clays much anymore so I almost never practice this way now.