Before I write a single line of code now, I ask a Claude Opus agent to rip the design apart - five minutes, every time.
Give it the design, ask for High/Medium/Low risks, ask it to call out any architectural patterns that'd be a better fit. We're only human - we miss things, we have blind spots, we get too close to our own ideas and stop seeing the gaps.
The bit that makes it actually useful is asking why. Why was that High? What's the failure mode? That's where the learning happens - not just "oh, good catch" and moving on, but actually understanding what you missed and why.
Use your own thinking first, always. Then use the agent to pressure-test it. Treat the output as a senior reviewer who doesn't share your blind spots.
It's caught some genuinely gnarly stuff, and it cost five minutes.
What's the most useful pre-code check you've added to your process?