Shallow frugality is miserable. Deep frugality is satisfying.
Shallow frugality is a perspective of scarcity. It causes you to look at your life and ask “what can I cut out, what can I sacrifice?” There is some value to asking these kinds of questions in the short-term, but not as a lifestyle.
Deep frugality is a perspective of abundance. Deep frugality asks "What value am I getting from this activity/expense? What is it I'm really after here? Is the way I'm spending money the most effective way to get the things I truly want out of life?"
With what you actually want defined, it typically becomes obvious that what you're spending money on might not be the best way to get what you're after. This is one of the earliest mental switches I had to make with developing a deep frugality practice.
With shallow frugality, you cut nonessential stuff out of your life, and figure out how to spend less to get the things you typically buy. You get more efficient, in other words. You say "I like playing video games. How can I play video games more frugally? Ah, I can stop buying games right when they come out, instead I'll wait for holiday sales on steam. I can shop around on ebay for last year's GPUs and components instead of paying top dollar for this year's stuff." The change to your lifestyle is essentially “the same, but with more constraints.”
With deep frugality, you go a layer deeper. You say "Why do I play video games - what is it I love about them? What do they bring in to my life?
“Hmm, well, they bring in challenge, the flow state, camaraderie with my guildies, a sense of improvement, and I really appreciate the art and the way they pique my imagination for fantastic worlds. Hm.
“Do I really need to play video games to get all of those things? I can get flow state and challenge from picking back up my leatherwork hobby which I already have the tools for, there's an awesome arts district just down the street I could spend more time at, maybe I can read books about imaginative worlds in fiction, oh and hmm that cafe down the street hosts tabletop gaming every Tuesday, maybe I could start doing that to hang out with friends I can actually see?"
And all of a sudden, you've arranged your life in a way that is richer, more fulfilling, with less negative side effects, and it happens to cost less.
Deep frugality isn't about being more ascetic than other people - in fact just the opposite, it's about using a process of close examination of what you enjoy in life to intentionally cultivate a lifestyle that's even more luxurious, rich, full, and bursting with what you want, than the unexamined, less intentional version of your life.
You said something about coffee…
In my frugality journey, I inevitably turned my attention to coffee. I'm no connoisseur - my sense of taste isn't refined enough - but coffee is important to me. Too important to drink burnt shlock, and too important to be okay with buying beans of questionable ethical background. Before applying a deep frugality lens to coffee, I probably spent $120 a month on coffee - $2/cup at home, and $3-4/cup at shops, 2-3 cups a day. $1,440 a year.
I found a source for bulk fair trade organic green coffee beans. I watched a few youtube videos on how to roast your own beans in a cast iron pan. I reflected on how I felt after my second or third cup of coffee.
I now drink one, sometimes one and a half cups of coffee a day that I roasted myself. I roast about every two weeks, so my beans are always fresh. A cup costs me fifty cents. I buy coffee drinks from shops a few times a year now, strictly special occasions. My annual coffee cost is now $180. I cut my coffee cost by 87%. And I get more out of the experience than I did before, I'm more intentional with it and don't spend any part of my day overly coffee-buzzed.
Far from any kind of sacrifice, a deep frugality perspective has brought more abundance and richness to my relationship with coffee. This is of course a small and simple thing, hardly worth mentioning. Maybe, though, the Good Life is nothing more than a composition of small and simple things, artfully arranged.
At any rate, my story with coffee is intended to illustrate the non-ascetic nature of deep frugality. Apply this lens to everything in your life (not all at once! that would be overwhelming), and soon your life becomes calmer, deeper, richer, more fulfilling, and oh by the way, much less expensive.
That last incidental attribute is a not-to-be-underestimated side effect in these uncertain economic times. You never know when a very low cost of living might come in handy.