There are three big things anyone can do to improve their game-play.
- Watch a replay or recording of your games; if you're lucky enough you can get someone to watch the replay with you and help you learn by pointing out what you need to do to improve. (You can also hire pro players, or high elo'd for an hourly fee to "coach" you.)
- Watch a stream, or watch other people play that are actually good.
- Read guides about this game; specifically: Mechanics such as lane manipulation, smart trading, pressuring, intelligent team-fighting, champion mechanics.
You can also go on the client and spectate challenger solo queue.
To do this in client you go: Profile > Leagues Tab > click the pull down box to go to the "Top Ranked Players" challenger ladder > An "eye" icon will be next to the name of a player that's in game. Right click that player and click "spectate game".
Generally, understanding the basics of this game and having PATIENCE in lower MMR can get you into platinum. Playing on a tilted or angry mentality can almost guarantee a loss. Understand that not all games are winnable, sometimes the games are just a lottery. Pick the roles that you find most enjoyable and look to improve from there. A good tactic to climbing to diamond is picking a single champion and mastering it, it's a little bit easier to do now with the new draft mode role selection. Muting players in game the instant anything is said that is negative can increase the chances of winning as well. The ladder is littered with smurfs and boosted players, if you ever find yourself losing it's best to take a break and maybe try again another day.
KDA is an interesting topic, sometimes it's correct to make riskier plays while most of the time the safer plays are the ones to go for. Generally the best thing to do is not die, but you still have to be able to make plays; just look for smarter ones.
A few "mechanics" for the roles you prefer: (There is too many things that are possible so just going to lay down some basics and are the things that come to mind)
Top lane:
-
Junglers can wreck you here. Top lane champions snowball the hardest. If you main this role you can generally get a good sense if something is up, trust your gut instinct. If you feel someone's waiting, just back off and wait for 10 seconds. This can do many things, it can help the wave shove towards you and make your opponents think that you're a safe player; they won't (hopefully) waste time trying to kill you. (This is true for all roles)
-
You do not need to take teleport here, but is recommended.
-
Generally trying to hit all of your cs is enough to be successful in this lane; as you get better you can start to solo kill/out-trade your laning opponent without missing cs (just remember to keep in mind the enemy jungler). The number one thing that makes or breaks the top laners is their impact on the rest of the map. Sure, some games is just you snowballing and possibly split-pushing to the inhib, but generally it's not like that and you'll just end up feeding from being collapsed upon. YOU WANT TO ROAM. Teleport is on a 4.5 second channel, it's some-what difficult to successfully teleport gank but it is possible (It requires your opponents to be 100% commited and way over-extended). A good tactic is to physically roam to a lane to gank them, then use your teleport to get back to your lane if need be. Smart roams are the key here, you can lose lane big time if you do it incorrectly. In soloqueue it's harder to get some mad teleport plays, just because the lack of good tp wards in the mid-late game.
-
Team fighting from this role is champion dependent, but generally peeling for your ADC (or team mates) is a fool-proof tactic that can grant an insane amounts of won team fights. (Yes, damage is in-fact a form of peel. Dead enemy > stunned enemy)
Mid Lane:
- Going to keep this one simple, because I feel it's the easiest role after support. (Smart) Roaming will win you games. Syncing your roams with your jungler is great as well. Generally this lane is harder to gank because of the length of the lane, understanding which champions can gank mid well and how they do it can help immensely. Generally shoving the lane and hanging back until the next wave comes is the correct way to play this lane.
Support:
- Vision is extremely important. Watching high elo'd games will grant knowledge on where and when to ward. Peeling for the ADC and/or team mates is the name of the game here, sure there is instants where engaging is the thing to do but in solo-queue and lower MMR'd games just peeling is so incredibly potent. Diving (engaging) is risky and sometimes if you have poor team mates you'll just end up dying. Janna and Alistar are two of my favorites, can peel incredibly well. Don't forget to auto attack your targets as well (don't force it or get out of position, your number one priority here is peeling for team mates) Stacking team damage even support auto attacks can drop the tankiest of tanks in the matter of moments. (Even if you're hitting 20's against the tank, hitting them 5 times is 100 damage)
With Nami, using her abilities to peel is potent, I see a lot of Nami's going proactive trying to engage with bubble, which is sometimes correct but it's easier to miss than if you try to hit an engaging enemy.
Being patient is incredibly important for this role. You will have adc's that suck mechanically, getting out of position, missing cs, etc... Just be patient and peel for them. Try not to die for them unless you know it's going to be worth it. The best support is alive support.
Going for aura's with items is great as well. (Locket, Frozen heart)
So generally (yes I say generally frequently because there is so much variance with league of legends and this is not obviously an in-depth guide to the game) keeping a good attitude and enjoying the game is the correct way to play. Grouping as 5 and team-fighting correctly is the best way to win games. Minimizing risky plays can help improve win ratios/kda. Farming/hitting all of cs and being proactive in the laning/mid game can provide fantastic results. Being patient and safe can result in enemies making game ending mistakes.
MAXIMIZING XP/GOLD PER MINUTE IS THE NAME OF THE GAME.
Season 6 has been great for the balance of the game, this is the first season I can confidently say that all champions are viable. Specifically ADC's.
Just find out what works for you that provides the winning results.