What are the things to check while reviewing code in pega?

What are best practices to followed while developing an application?

What are guidelines i need to keep in mind so that application be reusable?

I am expecting a list of things such as

1)Usage of parameters in rules such that rules are future proof and re-usable.

2)Use of getting current operator timezone than hardcoding GMT.

3)Use of when rules than expression in pre-condition and post conditions.

4)Usage of Circumstance Template and Circumstance definition than circumstancing the rule with a expression(.Property="ABC").

5)Use of class mapping than table names in query so that when we change the class to table mapping we needn't change the query.

6)Use of Dynamic class referencing than saving rules in implementation whenever possible.