Pondering on what means mastering the fundamentals of problem solving

Today I have been pondering what means "mastering the fundamentals of problem solving". I come up with few steps:

1. Practice small problems daily – e.g. use LeetCode, Codewars, or Edabit.
2. Always write down what the problem is asking.
3. Break the solution into steps before coding.
4. Use plain language first**, then write code.
5. Review others’ solutions to learn new tricks.
6. Try to explain your solution to someone (or rubber duck).