Seconding what was said above. I document *everything*.
I go out of my way to constantly be in communication with other hobbyists. I've rarely found anyone in this hobby who wasn't incredibly excited about sharing advice and strategies thatve worked for them, and I think I know why --this isn't the sort of thing most people excel at without being incredibly passionate about it!
I try different things yes, as often as possible, and exactly the way Gregg said: one parameter at a time. You have to approach it like a close approximation of a controlled experiment, slowly, with isolated variables and with the goal of trying to draw out some semblance of empirical data (or at least a couple notches above anecdotal data

but what I also do is I pay attention to when another friend and hobbyist tries something new. Almost everytime someone mentions something they're trying, I'm like, hey, take some pictures, keep me updated over the next few weeks. Hey, know we haven't talked before, but what you're doing is super interesting, mind explaining your logic behind it?
Basically I bug people constantly

but we always have a really cool discussion. A couple sayings are just as true here as anywhere else...surround yourself with people who do and know better and more than you. And also, as important as it is to study those better than you, it's just as important imo to teach those a little fresher than you. You don't truly understand something until you can break it down and explain the what and how of it to someone who only knows about 75% of what you're talking about. Aside from doing what I think is a really important duty of making the hobby more widespread and open to all, I think it's a great way to reinforce and refine knowledge you thought you already had.
The tip about emulating styles is an important one too. I like Dutch, that's my eventual goal, nice Dutch tanks. So those people I talk to most. A good Dutch amounts to having near perfect plant knowledge, husbandry skills, and placement experience. So those are the things I focus on. I can plant a really nice tank, I can maintain a really nice tank, I can grow the hell out of some plants. But I couldn't put a rock in it to save my life


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@GreggZ can also vouch for that, he's seen me struggle first hand)
The stuff people do with hardscape is absolutely beyond me, because it's not the style I'm going for or interested in.
Linn mentions SC here being a perfect place to learn--it is. Take in as many resources as you can but there's something about forums and the way data and info is organized and always available to reference that's invaluable. More importantly, you get something that YouTube videos don't have, which is a community of great minds developing. Having learned a lot of what I know from some of the people here, I can safely say that we 100% have some of the greatest here.
YouTube videos are good for some things but I question the integrity of info when someone's selling something, and while they're great for shallow coverage of broad subjects, the information's gonna be diluted on purpose in order to reach a wider audience by it's very nature.
So yeah...to summarize, I asked alot of questions on groups and forums. And when I needed to know more and dive a little deeper, I just started hitting people up out of the blue

I do it to people when I buy, sell, or trade plants too. Every single time. Doesn't matter if it's a picky species, if it's something I've never grown before, or if it's a plant I'm getting rid of that I've been propagating since day one. I am going to ask you how you're growing it, and in what conditions, and why that way, and why don't you do it this way, and we'll what's your maintenance schedule like, and hmm idk that PO4 looks awfully low to me but if you say so

I just ask ask ask, shamelessly.
So please know that if you send me so much as a Java fern, you're getting grilled on it.
That's a joke of course but hell, rotalas a common weed and Vin was able to draw some pretty badass conclusions to how they can actually be some of the pickiest species in regards to nutrient uptake.
There's always something to learn

and that's what keeps me coming back