"Back up, think again, take dead aim" is a better strategy than "Brew, rinse, repeat."
I know a genuinely tone-deaf person. Can't carry a tune in a bucket. No matter how many times I hear him/her singing the same songs - Christmas carols, country songs, anything - it's a tuneless, cringe-inducing (but well-meaning) mess.
Practice doesn't make perfect. The best we can say is that practice, by rote and over a long stretch of time, generally guarantees some level of improvement. Real progress takes more than reps, though. When it comes to brewing, improvement (at all levels - not just for beginners, and we should all be looking to improve now and again) takes, in my humble estimation, three things:
1. Strategic retreat/evaluation
2. Education (or re-education)
3. Deliberate practice (as the likes of Prof. Anders Ericsson describe it)
One Step Back, Two Steps Forward
Human beings aren't big fans of revisiting things, especially when they seem to work. "Don't fix what isn't broken." "Don't change horses in midstream." "The squeaky wheel gets the grease." The problem with that thinking is that too often we're not finding solutions to our not-yet problems.
Problems aren't just "things that are negative." They're things we seek to fix. Problem recognition is not automatic, and we have an innate bias against seeking out problems.
Step one, then, is to take a step back and evaluate the effectiveness, efficiency, and sustainability of your brewing practice. However good your beer is, I promise you that you're doing something that could be improved upon, if only you'd take a beat and think about it. I can also promise you that you've added something to your process that isn't giving you any real benefit and can be eliminated. Back up. Reevaluate.
It might feel like regression: it isn't. Every few months I buy new and different hops. Every bulk grain buy, I buy more of some grain that I know I don't need to force me to try new recipes. I think about whether I need more output, or less. Being self-critical as part of a regular regime of improvement isn't putting yourself down, it's urging yourself up.
All Knowledge is Provisional
Some posit that all knowledge is provisional - that everything we "know" should be treated as "correct for the moment, but subject to revision." That kind of epistemological humility is especially important for brewers, because brewing science and practice are still evolving pretty rapidly.
Some of that is because it's the subject of a lot more interest today than in previous generations, but it's also because we're constantly trying to adapt the lessons of commercial brewers (or of other homebrewers, whose skill and diligence we can't evaluate easily) to our own process and approaches.
Short version: what you believed to be true last year about brewing might no longer be accurate. At the same time, things you thought wrong or impossible might now be known to be preferable. How do we know the difference?
Some of this is live-and-learn (just naked practice - hey, I didn't say it was worthless, just that it doesn't make "perfect!").
However, if we want to improve we also need to reconsider what we "know" in a formal sense. We need to educate and, potentially, re-educate ourselves. Read new books. Seek out new articles. Attend conferences and classes. Go through a formal certification process like the BJCP or Cicerone exams to compel learning and skill development.
At the same time, see if any new technologies, ingredients, or developments have given us any new tools to solve previously-intractable problems. Hop extracts and hash and power are now readily available. Mini-barrels can be had for wood-aging in small batches. New and rediscovered yeast strains are on the market. Reconsider what's "possible."
Doing this, though, requires us to be willing to challenge what we know. As John Stuart Mill said in "On Liberty":
"However unwillingly a person who has a strong opinion may admit the possibility that his opinion may be false, he ought to be moved by the consideration that however true it may be, if it is not fully, frequently, and fearlessly discussed, it will be held as a dead dogma, not a living truth."
Practice with Purpose. Practice with Purpose.
There's practice, and then there's deliberate practice. For a great rundown, check out this episode of Freakonomics radio. The short version is that if we want to improve, doing the same thing over and over is a pretty poor way to do so. What we need to do is to practice and train at the limits of our abilities so that we force our brains and bodies to find new economies, solutions, and methods.
For brewers, the best way to do this might be to brew to exacting standards and compare our output to real benchmarks. One great way to do it, and the one I recommend most often?
Cloning beers is tremendous deliberate practice. It requires us to source or create a recipe, brew exactingly to it, adjust, brew again, adjust, brew again, and all the while comparing what we made to what we were trying to make. We'll start identifying variability that we need to clamp down, we start to learn how ingredient or process changes affect what we produce (and by how much), and more.
To quote golf teaching legend Harvey Penick, "take dead aim." That's what cloning requires.
There are other approaches, too, of course. Challenge yourself to make a beer under 4% ABV or over 10% that is usually 6%, but with no perceptible flavor changes. Duel, with two brewers brewing the same style or even the same recipe. Brew new beers all year long to break yourself out of ruts. Introduce a new process or method that you discovered in your "education" step. Anything.
Cloning is best, though. Anyone can shoot an arrow. Shooting an arrow off the top of someone's head is a real test, though - especially if you like the person (and maybe even if you don't, if you know what I mean...). You could stand in an open field and fire off arrows all day long and not improve, but it wouldn't take too many near-and-dear relatives getting shafted (so to speak) before your aim ticked up out of sheer concentration and stakes.
The preceding all presumes that you have any desire - even just a little - to get better. If you don't, and this is just a fun pastime for you, then that's AOK, of course. I know a guy who goes "fishing" all the time and never catches anything, and isn't really interested in it. He likes the quiet and the sunshine, and the fish are incidental.
If that's you, then there's not a thing wrong with it.
Let me say this, though: however we like to brew and for whatever reasons, we can usually do it better, cleaner, faster, or cheaper. If you're just a "fun" brewer, then think about inviting over some friends to brew, too! If you like what you brew and don't want to change it at all, why not see if there's a way to brew more varieties of it?
If you're a pure "Relax, Don't Worry, Have a Homebrew" person, why not try brewing while doing yoga?
For those who are working to improve in any way, though, this little treatise might be of some use to you.
Just don't tell me that "practice makes perfect."
Keep it simple.