There is no forgetting the safety on your gun if you train with it to the point that you do not need to "remember" because it will be a reflexive muscle memory and switching it off or on is done without thought, automatically.
It sounds as if you may have too many guns with too many different systems of operation. I suggest safeing all but one and train train train until it becomes ingrained in you. Then go to the next weapon and do the same thing. Be safe and diligent with your safety practices.
"Always place your clothes and weapons where you can find them in the dark"
"Understand that the enemy is not the enemy in his own eyes ;this may offer you an opportunity to make him your friend. If not, you can kill him without hate, and quickly."