This worked for me.
I broke up the draw into pieces and worked on them individually.
First I set a par time of like 0.6 or so, and just work on reacting to the front of the beep, and get your hand to to gun. I did this for a few minutes.
Then,
Same par time, start with hand on gun, and draw to a target. I did this for a few minutes. Do NOT pull the trigger.
Then,
I put it all together, with a 1.0 sec par time, but do NOT pull the trigger.
Why don't pull the trigger ?
I will be too easy to cheat the drill. To pull the trigger before your sights are on the target.
And
Once you get better, and can get your sights on the target in 0.8 the extra time will allow you to let the sights settle. This visual patience is also an important skill.