How You Do Anything
How you do anything is how you do everything. As a parent I find myself saying that quite a bit. I put on my stern lecture-y dad face and always start with a slightly puzzled sounding "You know…". I mean it too; it's been my experience that if I let myself cut a corner even just a few times, I'll probably end up making that my standard approach.
Of course I'm better at giving vs following when it comes to advice. I've always been a tinkerer, I make lots of little IOT apps. I create simple web based games to see how different libraries work. I just generally like to play with code, but I almost never approach this work the same way I do when I'm building out something professionally.

There are a host of reasons, the cost/value proposition is vastly different when I'm just tooling around. Also I like to be as fast as possible when exploring new things. Lastly, it's a question of durability. Much of what I build for myself will be short-lived, a few weeks at most before I'm on to the next thing.
But if how I do anything, is really how I do everything — doesn't that mean I'm creating bad habits that might leak into other areas of focus? I really dislike this type of question. I can give myself a mostly honest answer that lets me continue preaching the right way to do things while giving myself a pass. If I'm honest with myself, I probably need to admit that I need to be more contemplative around the risk/reward models of consistency.
I don't think that means that I need to start with TDD when I'm tinkering with Victor.js to create an ASCII pool game, but I do think it means I need to check my enthusiasm when it comes to building something new and trying to get it committed & pushed as fast as AI+humanly possible. The real lesson for me is to spend more time understanding the value. If I want something to be durable, usable and maybe beneficial to someone else, I should treat it like a professional project. I should think about the steps I would take, and if I decide to bypass them be explicit with myself about why, what the risk is, and what I really hope to get out of the project.