Constantly try new things and if something works stick to it and do more of it.
Beware of exceptions.
I am not advocating doing one thing forever just because it worked before.
Always try new things and if new works better, replace old (and do more of it).
But beware of exceptions.

Here are two examples from business and personal life.

At Chefparade we have elaborate 4 steps process for hiring people.
I have described it in this post.
All people who went through this process are good performers and long time with company. Last year we made exception and hired someone who did not go through the whole process.
He’s no longer with us and it was costly mistake.
For next round we do no exceptions and added 5th step to make sure this will not happen again.

Last year I went on 6+1 diet. That means 6 days zero carb, 1 cheat day eating anything.
I lost like 2 inches from my waist in 3 months only by sensible eating.
Later on, I loosened my standards.
Exceptions started to crawl in. Beer here or there, sandwich or ice-cream.
Just this one, just today.
Result? 1 inch gained back.

Looking back at the exceptions I have made in business and in life,
none of them was worth breaking the rule.