A prompt like “Write a $x program that does $y” is generally going to produce some pretty poor code. You generally want to include a lot of details and desires in your prompt. And include something like “Ask clarifying questions until you can provide a good solution”.
A lot of the people who complain about poor code generation use poor prompting.
Simon Willison has some great examples in his blog and on his GitHub. Check out Karpathy’s YouTube videos as well.
I've been developing my prompting skills for nearly three years now and I still constantly find new and better ways to prompt.
I also consider knowing what "use a reasoning model" means to be part of that skill!
I just tell the AI what I want, with sufficient context. Then, I check the reasoning trace to check it understood what I wanted. You need to be clear in your prompts, sure, but I don't really see it as "prompt engineering" any more.
As with any other project, it’s best to specify your wants and needs than to let someone or an LLM to guess.