OpenAI has come out with a GPT-5 Programming Hints Tips Guide with six points

Directives need to be precise in order to avoid conflicts: GPT-5 is more capable of following them, but is prone to jamming or shaking in the face of vague or conflicting rules, and should spell out requirements and eliminate conflicts; and it may be counterproductive to avoid overstretched: “It is essential, necessary, necessary”. Selecting on the strength of reasoning and the use of type XML syntax structured rules: complex tasks are highly deduced and conventional missions are medium/low deduced; type XML labels are used to assign projects, technology stacks, style baseline sections to help model to create a uniform context; zero-to-one tasks are planned for self-saving work: models are defined (but not presented to users) and they are produced in an iterative manner; and the Agent tool budget and search rhythm can be controlled to specify when and when to examine and report and avoid overdeep。