I haven't written tests as part of my regular workflow in... years now, but one of my earlier mind blown / level up as a developer was when I wrote tests, which made it required that my code actually had to be clean and conform to a load of best practices that weren't in my mind's eye yet.

The other day I was doing a part of Go Blueprints which touched upon TDD; one thing it highlighted was that if you use TDD you should only write until your test is green, no more - this (supposedly) avoids you writing too much code. It has some merits. I'll need to do a lot more TDD and co to actually see it though.