This is what my husband calls the ongoing habit/ practice of financial savviness that is usually at the forefront of my mind. I would say that the underlying principle of the Culwell Doctrine is to try to integrate savings into your life in a painless way, so that you end up with more money for doing the same things. This could include anything from asking for a discount for a service you use all the time (like dry cleaning), regularly checking your credit card bill to make sure you didn't get charged hidden fees (I've caught Chase Bank doing this more times than I'd care to mention), or just comparison shopping before you pull the trigger on a big item like a TV. Overall, I don't find that these things take alot of time, and they can potentially save you a ton of money.
So, no-- I don't make my own yogurt, or do craft projects where I make picture holders out of empty milk cartons. The Culwell Doctrine only extends to things you are already doing and trying to optimize those a little bit, not adopting totally new habits (unless that's something that interests you).
