Pretty boring with ChatGPT Pro, ghostty, CLI harnesses, and vscode if I feel like looking at the code.

If it's a brand new app I will design with the agent up front to make sure we're capturing everything and it is actually driving toward a specific outcome or else it can wander into 'productivity porn' territory where it's just creating reams of reports, plans, or 'evidence packs' and nothing real gets implemented.

I used to use a lot more sophistication in my workflow and skills and I still do use a few (impeccable is great for de-sloping design) but they've gotten a lot better at breaking down a plan and building without that.