This introduction video is designed for people just getting the SIRT training pistol and want to begin training. A great place to start is trigger control. Many shooters have some issues with trigger control where definition of trigger control is the ability to not disturb the muzzle while breaking the shot. With the right-handed shooter a lot of trigger mechanic deficiencies are hooking where the gun is tilted to the left (for right hand shooter and jolts to the left for a left hand shooter).
Shooting strong hand only can really identify trigger mechanic deficiencies.
Try shooting strong hand only with a SIRT and work that laser impulse into a dot and not a dash.
Trigger finger placement is a factor but not necessarily critical. Try placing the finger in a natural location than the trigger guard when it touches the front part of the trigger. Wherever you touch the trigger, try to bring that portion of your finger straight back, straight back to the flesh between your knuckles of your forefinger and your thumb. Continually work on your trigger mechanics to try to perfect them as much as possible for not just slow aim fire but also with rapid shots.