In what may be a series (if people find it useful) I'm going to be talking about some of the "basic" DOTA skills that are often overlooked, or only understood on an unconscious level.
These are "mechanical" and "instinctive" skills that you rely on to execute plays. For example, accurately clicking the right parts of the screen, hitting your combos, dodging incoming projectiles, body blocking, and many others.
These skills need to be learnt, and internalised to become fast and reliable enough to survive in a fast paced game of DOTA. Simply put, you need to be able to just think about what you want to do, and your hands to do the rest - not about what keys you're pressing.
The first part is going to be around positional skills. They're very hard to describe in text, and the game is so situational that it's not something you can understand through a few easy points. There are so many different heroes, items and abilities that there's no one size fits all. Behind a creep might be a great place to stand with
Pudge around, but a terrible one with 
Windranger hunting you.The best example I can think of with this is, the concept of "Maai" - from wikipedia:
"Maai (間合い?), translating simply to "interval", is a Japanese martial arts term referring to the space between two opponents in combat; formally, the "engagement distance".
It is a complex concept, incorporating not just the distance between opponents, but also the time it will take to cross the distance, angle and rhythm of attack. It is specifically the exact position from which one opponent can strike the other, after factoring in the above elements.
For example, a faster opponent's maai is farther away than a slower opponent. It is ideal for one opponent to maintain maai while preventing the other from doing so,[1] meaning that they can strike before the opponent can (rather than both striking simultaneously, or being struck without being able to strike back). "
This is an interesting idea as it's not just about physical distance, but about the distance that your opponent can attack you, and vice versa. Not just their right click, but their abilities and movement skills that can allow them to successfully attack you.
So example
Ursa has a very short maai range - he can only attack and/or control opponents in a very small area. If he can move faster than you, you're then reliant on your own control abilities (slows and stuns) to keep him away from you. 
Crystal Maiden for instance can only safely move closer to him when 
Frostbite and 
Crystal Nova are available to her to keep him from chasing her down.If you have better mobility, you can afford to stand closer on the basis that you can quickly disengage if you get into trouble.
Once he gets a
Blink Dagger, his ability to close that range and attack you increases greatly, and you have to treat ole Fuzzy Wuzzy with a lot more respect in terms of your distance from him.On the other hand, a defensive ranged support should generally be in position behind their core - close enough to help or save them, but not so close to leave themself a target.
Maai is especially useful during the laning stage - being aware of when you can safely harass, stand closer or drive away your opponent. Try to internalise the concept as much as possible, and use it to inform your positioning relative to both your allies and opponents.
For episode 3, I'd like to see you tackle how to choose which Items to buy. 8{3