First of all, if you look at this post and think "hurr durr too long", then feel free to gtfo, I'm posting this for people that want to improve, not for people that want to read a quick sentence. 
Now, these tips are for those of you that have played all heroes at least around 5 times each and that know how to play every hero the standard way, these tips won't help much if you aren't at least at the level I just mentioned.Some few very basic tips first, which sadly most of you still have no clue about. These tips will "solidify" your gameplay, they will make it stable:1.
Watch the mini-map every 10 seconds at most, with NO EXCEPTIONS, for ALL GAME DURATION.
, and do not watch it just so you say you watched it, get information every time you watch it, if you can't, then practice until you can.
2. Use your brain while playing, not some random irrelevant guide which 99% of the time does not apply to your current particular game. You should instantly know what is one of the best ways to play and what are some of the best items to get against the enemy heroes, if you can't, then practice until you can.
3. Be aware of everything that is happening in your current game, on every lane, for every hero,
at every single moment. Who is the highest level on the enemy team ? Who is farming the most ? Who they will probably start ganking ? What lane should we push ? What lane should they push ? When should they push ? What is the best way to play for them, what to do against it ? What is the weakness of their heroes ? How to amplify their heroes weakness ? How to improve our heroes strenghts ? What are our heroes strenghts ? What are our heroes weaknesses ? How can we fix them ?
(if they aren't visible: Where could they be ? What could they do ? What should we do ?)
These, and MANY more, are all questions which you must be able to answer
instantly, at every single point in the game, if you can't, then you need to improve a lot, and practice until you can.
4. Be aware of your potential to kill in certain situations and to get killed in certain situations, stop fighting like a braindead monkey and consider everything that can be considered before fighting if you want a good outcome 100% of the time, assuming you don't fuck-up somehow, if you can't, then practice until you can.
Now, some few tips that push your skill level forward. These tips WILL make you lose a lot, but that is irrelevant, you are looking to improve your skill level here, that cannot be accomplished with easy wins and standard way of playing:1. Forget almost all things you think you know about dota (not hero hotkeys and stuff like that
).
Have an open mind about everything, and reconsider every single action you take, think about alternative ones.2.
Do not care about counter-picking, in fact, you should
pick a clearly inferior hero, a hero that is clearly heavily countered by the enemy picks, that way, you will usually experience a much harder game and if you actively use your brain while playing, you will improve far quicker than playing a clear counter to the enemy picks, which usually results in you clicking a button and your enemies dying, in which case you learn nothing.
3.
Do not care about standard ways of playing heroes, and go for new ones, which will be most of the time much harder to play than the standard way, this means even if you think it isn't suited for some hero to do something, do it, see why he shouldn't do it, maybe you'll discover that he actually can do it, and that he can actually do it far better than other heroes.
This is actually the case for many heroes, but well over 99% of players do not realize it,
not even actual professional players that are sponsored and play in tournaments for money.
To elaborate a bit more here, very many "cores" can be played quite successfully against quite a lot of line-ups as an aggressive support, the other way around it's a bit more rare, but it still happens, and again even professional players that are sponsored and play in tournaments for money are very slow to adapt to this idea, and most of them do not even consider it possible.
(For cm/cd games: This also has the benefit of being extremely unexpected (because most players don't consider it), and it will leave the other team most of the time baffled and unprepared to your draft.)
These should keep you busy for a while, feel free to ask me anything and I'll reply when I got time.
WiKi
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