I basically use a spec driven approach except I only let Github Spec Kit create the initial md file templates and then fill them myself instead of letting the agent do it. Saves a ton of tokens and is reasonably quick and I actually know I wrote the specs myself and it contains what I want. After I'm happy with the md file "harness" I let the agents loose.

The most frustrating issues that pop up are usually library/API conflicts. I work with Gymnasium or PettingZoo and Rlib or stablebaselines3. The APIs are constantly out of sync so it helps to have a working environment were libraries and APIs are in sync beforehand.