You need to train/practice with your guns until disengaging the safety becomes 2nd nature.
Just the same as making sure it's operating characteristics are 2nd nature. Pump if it is pump operated, cycling the bolt, pushing the magazine release, pushing the cylinder latch forwards instead of in or down, etc.
Just because you leave a safety off, doesn't mean that it won't somehow get put back on. Murphy's Law always wins.
Practice, practice, practice.
It can also help to get a many weapons types as similar as you can, HD shotgun the same as your upland game gun which is the same action as your duck gun and the same as your trap gun etc. This is what I do.
Benelli shotguns, AR-15 type rifles, Glock semiautos and S&W revolvers.
As a matter of fact, just for fun yesterday I took out my Dad's old Browning BPS to go crow hunting with. I kept trying to double check the safety behind the trigger guard.
