You could try out Prompta [1], which I made for this use case. Initially created to use OpenAI as a desktop app, but can use any compatible API including Ollama if you want local completions.
I use similar ones to get ChatGPT to be more thorough or diligent as well. From my limited experience with local models, this type of system prompting is even more important than with ChatGPT 4.
There isn't a singular system prompt. It really does matter!
Copy the OpenAI playground, you'll thank yourself later