re: Shot my new to me 357 magnum today for first time.

I'll tell you what helped me with a Model 66 more than every tip I read: a lasergrip. The 66 has a very smooth trigger pull but it's still a double action trigger pull and it takes practice. Although I didn't buy it for that reason I soon learned it excels at showing you what the muzzle is doing as you pull through, and you can dry fire it all you like from the comfort of home. I didn't even look at the sights, just held it in a variety of postures, working on making the laser move as little as possible. Sight picture is a sight picture once you get the muscle memory down.

It's also useful for snap aiming. Pick a spot, bring the gun up and point, hit the laser button to see how close you are.