Should you ever need a variable that is not changing over time (or in many cases just one time), you should use constants. Constants are quick-to-find variables and they help you minimize memory usage.
The term ‘configuration’ means variables that are used a lot and rarely change but can be changed in the middle of execution, if needed. Constants can be made as configurations if it can be changed in the middle of execution. Otherwise, leave it as a constant.
So many programmers don’t care about access-level modifiers. If you need broader access, use protected and, as a last resort, public access. This way you can protect your specific method or member from the ‘outside world’.
Comments let you remember code snippets, algorithms, sort methods, even randomized numbers you’ve created before. This is a big advantage if you’re working on a team. Because of comments, other people will understand your intentions.