Ruslan L
Legend
Platinum Level
I actually learned only from my own mistakes. I've never liked learning. I've always preferred to practice without learning. Although in general I understand that training is necessary if a player is serious about poker. If I had joined the CardsChat community when I started, my progress would have been much faster.
havingfun
Rock Star
Platinum Level
I watch videos of popular poker players and take into account their reasoning for making certain decisions, using that info to hopefully improve my game.
Then most importantly, I feel playing helps to improve you the most as you see what works and what doesn't.
Then most importantly, I feel playing helps to improve you the most as you see what works and what doesn't.
s0ftdumps
Rock Star
Platinum Level
I like watching ryan depaulo and his hand break downs. keeps it fresh and not stale
john_entony
feed the Fox
Loyaler
CardsChat has helped me a lot in my case. There are many very good players here, from whom I try to learn the best variation of poker styles. But practice is also very important. This means that watching training videos and reading poker books are not enough. You have to analyze your mistakes every day, correct them and move on towards perfection. 
sandy358
Rock Star
Platinum Level
Theory videos, charts, solving the toy games with my own deck
D
drogus
Rising Star
Bronze Level
I see a few answers that just say "play more". I don't think it's a good advice. Playing poker for practice is beneficial, but it will only take you so far. It's really hard to come up with a sound strategy by just playing, especially with all of the resources that many players are studying. Let's take something as simple as pre-flop ranges as an example. Would you be able to figure out solid set of ranges by playing alone? Yeah, most probably you would, but how much money do you have to spend doing that? How many thousand hands do you have to play and experiment with different ranges in order to figure it out? Whatever the number is, it's probably quite big, unless you are some kind of a natural poker genius or sth (which I'm sure most of us are not).
When studying poker, I think there are a few "low hanging fruits". First of all, study the pre-flop ranges for raising and calling in various positions, and ideally also 3-betting. Refresh them from time to time. Don't just learn percentages, either. Ie. you don't want to remember that from a certain position you play 30% hands, cause it's hard to learn what exactly 30% of hands is. Once your pre-flop game is solid, the post-flop play becomes much easier cause you will end up in weird spots less frequently, and you will probably win more hands without even seeing the flop.
Second, look for articles and/or videos about certain topics, like: c-betting, 3-betting, ICM (if you play tournaments), check/raising, bluffing, implied odds etc. Whenever you are in a tough spot, write it down somewhere and later on try to find information that might help you in the situation. You lost with AK? Look for strategies and tips on playing with AK, and most often you will find some decent info. With this example, you might for example end up watching Stop Losing with AK by Jonathan Little. And then you will, for example, learn that you might not necessarily hold on to you AKs post-flop when you don't hit any hand post-flop.
Third, watch streams/videos of people playing on stakes similar to what you play. Ideally, winning players. Even more ideally, players that discuss at least some of their moves.
Fourth, study probability. How certain hands stack against other hands (like AK vs QQ etc). What are the percentages for flopping a hand (like: how often will you flop a set with a pocket pair, how often will you flop a straight with connectors, how often will you flop a flush, or how often will you flop a flush draw with a suited hand). What are the percentages of making a hand on turn and on the river, for example, what is a chance of getting to a straight on a turn with a connectors hand. Also what are the percentages of making a hand on turn or on the river when you are already on the flop or on turn. Match that knowledge with calculating pot odds, implied odds etc.
Fifth, study bet sizing. Learn how to size bets in certain situations (like value betting, protecting vulnerable hands etc) and how to get a certain outcome (for example, how much to bet to make a middle pair to fold).
Sixth, review your hands. You don't have to review all of them, but review especially the hands that sting the most. The hands that you know, or at least you suspect, you played badly. Hands that you can't forget. Hands when you thought you will totally win and yet you lost. Hands where you lost big pots. Hands where you ended up in a situation with a question "what now?" and no good answer. Put the hand in the solver, or ask on the forum, or try to find similar situations online.
When studying poker, I think there are a few "low hanging fruits". First of all, study the pre-flop ranges for raising and calling in various positions, and ideally also 3-betting. Refresh them from time to time. Don't just learn percentages, either. Ie. you don't want to remember that from a certain position you play 30% hands, cause it's hard to learn what exactly 30% of hands is. Once your pre-flop game is solid, the post-flop play becomes much easier cause you will end up in weird spots less frequently, and you will probably win more hands without even seeing the flop.
Second, look for articles and/or videos about certain topics, like: c-betting, 3-betting, ICM (if you play tournaments), check/raising, bluffing, implied odds etc. Whenever you are in a tough spot, write it down somewhere and later on try to find information that might help you in the situation. You lost with AK? Look for strategies and tips on playing with AK, and most often you will find some decent info. With this example, you might for example end up watching Stop Losing with AK by Jonathan Little. And then you will, for example, learn that you might not necessarily hold on to you AKs post-flop when you don't hit any hand post-flop.
Third, watch streams/videos of people playing on stakes similar to what you play. Ideally, winning players. Even more ideally, players that discuss at least some of their moves.
Fourth, study probability. How certain hands stack against other hands (like AK vs QQ etc). What are the percentages for flopping a hand (like: how often will you flop a set with a pocket pair, how often will you flop a straight with connectors, how often will you flop a flush, or how often will you flop a flush draw with a suited hand). What are the percentages of making a hand on turn and on the river, for example, what is a chance of getting to a straight on a turn with a connectors hand. Also what are the percentages of making a hand on turn or on the river when you are already on the flop or on turn. Match that knowledge with calculating pot odds, implied odds etc.
Fifth, study bet sizing. Learn how to size bets in certain situations (like value betting, protecting vulnerable hands etc) and how to get a certain outcome (for example, how much to bet to make a middle pair to fold).
Sixth, review your hands. You don't have to review all of them, but review especially the hands that sting the most. The hands that you know, or at least you suspect, you played badly. Hands that you can't forget. Hands when you thought you will totally win and yet you lost. Hands where you lost big pots. Hands where you ended up in a situation with a question "what now?" and no good answer. Put the hand in the solver, or ask on the forum, or try to find similar situations online.
M
MatheusANF
Rock Star
Bronze Level
Which players?