For LCS games go to the Fiss Mortune.BLACK channel on youtube; they post every LCS game that's cast in English. Watching LCS is good to learn how to improve your overall team performance, so it's good to watch a few games a week. Plus, they are always really entertaining.
However, LCS doesn't really help you learn independent laning mechanics because they tend to bounce between lanes, only focusing on the action. Watch a pro streamer on
www.twitch.tv and clicking League of Legends--any on the recommended list are good to watch. For ADC I recommend watching phy because he actually commentates on what he is doing; a lot of streamers just play. It's good to watch from the actual desktop perspective of the player because you can pick up on a lot of things that you don't gain from the LCS.
Other than that, focus on learning the meta. I think it's a load of crap to say that "any champion can win any lane against any matchup and work with any team." If you keep trying to play a non-meta champion in lane, you'll find that the A-tier picks really
are better. Even if you think Ashe is fun to play, she's not a good pick because she doesn't fit into the meta of what style of ADC is preferred.
The meta itself is really complicated, but in general:
1. Mobility is the most significantly overpowered statistic right now. Nearly every A-tier champion has a dash or mobility enhancement. Interestingly, to prove this point, one of the best-tier ADCs is Sivir, who theoretically should be the worst. Her base stats are hideously low; her attack range is the worst of all ADCs, and her ultimate does not improve her damage. However, mobility is so overpowered that her 40% movespeed buff on her ultimate makes her go from "really, really underwhelming" to "really, really overpowered."
Also, to help prove mobility's OP nature right now, look at the common bans. Almost all of them have ridiculously strong gap closers.
• Kassadin has the strongest "blink" in the game; he can blink across a fight for a huge range and the cooldown is only a few seconds
• Vi has a really long-range dash and an ultimate that is also a dash
• Wukong has a dash
• Leblanc has spell that can count as a double-blink
• Pantheon has a dash and his ultimate allows him to basically teleport
2. Tankiness is cheaper to buy than pure damage. Of course, this is only assuming an "even trade" where noone is avoiding the damage by juking skillshots or remaining out of range. As an ADC main, pure damage is obviously preferred because you are
expected to avoid taking damage. As a top lane melee, however, you should generally stick to only one or two damage items.