I have a $20 Claude Code and a $10 Opencode Go for personal use. Work pays like $150/month for Claude Code use there. Like in another comment I put A LOT of context in Obsidian and agents log their work there.

Workflow-wise I just have a small GTD-ish setup with lists for inbox, todos etc and a couple of paragraphs describing how I want the coding process and troubleshooting processes to be handled.

The bulk of my instruction set is about communication style, since the defaults give me hives from the sticky tone and burnout from the sheer amount of words in the output. All of it works to keep answers short, to the point, sticking to technical details and absolutely no linguistic decoration or polite stuff. The most effective line I have in my Agents.md is to answer me like a Vulcan rather than a human.