Human hand is designed in a way that the two shortest fingers usually are the pinky and the thumb.
That's why it's difficult for them to reach the sharps. It's especially true when the keys are short on ancient organs.
The exception is playing the chords and wide intervals - often you need both of them (especially the pinky).
So use the longer fingers (2, 3, and 4) as often as you can on sharps.
Not only you will avoid many mistakes but your hand will thank you for that.
Just like your back, if you keep it straight when picking stuff up from the ground.