If I'm shooting with iron sights at 50 or 100 yards. I like to use "shoot and see" targets that are roughly 16" tall, and 6" wide. If I'm shooting, and using optics, I normally use 5"-6" "shoot and see" targets. If I'm shooting pistol I like small silhouettes or 5"-6" "shoot and sees".
For 25 yard rifle practice I shoot 1" squares and reduced silhouettes. For >=100 yard rifle and all distance pistol I use bobcat steel 4", 8", 100% torso targets.
I use free handgun targets from google, the ones that are circular and will tell you if your pulling the trigger, or your pulling left/right, anticipating recoil...ect...