There's one general mistake most people make whenever they're playing ADC - which is not properly kiting targets. It sounds very easy to kite, in theory; right click any enemy, right click backwards, right click any enemy, right click backwards... seems easy, right? But what happens if you click ever so slightly off within your movement and now it's instantly ruined and you now get greeted by a very familiar grey screen? That doesn't sound so amazing now does it?|
Plenty of players missclick all the time, and honestly, it's a very common occurence even with myself. Most good players (and especially Challenger tier ADC players + Pro Players) aren't affected too badly by these random missclicks, and the main reason for this is because of a built-in setting in League called "Attack Move".
Attack Move is a setting that acts very similarly to a regular right click; if you attempt to use attack move onto an enemy, you'll obviously attack that enemy, and if you use attack move and right click towards the ground, your champion will move towards that spot. The difference between using Attack Move and regular right clicks however is that if you move towards the ground, your champion will stop to auto-attack an enemy if they run into one before they reach the destination they originally intended to get to.
To any inexperienced League of Legends player - this seems incredibly useless, I mean it sounds just like a regular right click with no benefit whatsoever? However it actually has a multitude of different uses. For example kiting, if you right click backwards, then attack move your enemy, then right click backwards, rinse and repeat - congratulations you've successfully kited an enemy champion. Another significant detail about Attack Move to keep in mind is that it will always target champions when used, this means that if you're let's say diving an enemy under their tower - you won't have to worry about accidentally missclicking your auto attack onto the tower.
Kiting targets is the more obvious area of expertise for ADCs in which Attack Move becomes almost invaluable, as it'll save your life so many times, maybe even a multitude of times during a single game if used well. There is no downsides to using this setting for kiting and there are only upsides in what it's able to provide for you.