Easy ways to improve your ranked performance WITHOUT getting better at the game!
As the title says. There are a few super simple things you can do to put an edge on your ranked performance that requires no skills, gameplay knowledge, or map awareness. With this quick tutoriwall-of-text, you will learn how to convert laziness and forum browsing into mild to moderate improvement in your ranked career, today!
First things first: Never troll, give up, leave, or flame teammates. If you can count on yourself to never throw game and always play your best even when a game looks bleak, you put you and your team at better odds of winning. As for flaming, you don't improve your chances at winning by trying to sabotage the mental state of the people you're depending on to help secure victory. This includes firing back at a toxic player on your team, because not only do you split your concentration from the game by focusing on what they say, but you will usually either make them more toxic or even more tilted than they already are, which reduces your odds of winning. As far as you're concerned, there are only 4 wildcards on your team that might troll, give up, leave, or flame. The enemy team has 5, which puts them at a disadvantage, but only if you do none of these things yourself!
Next up, don't exclusively play ranked games. There are benefits to playing normals once in a while that are covered in later points. Don't hold onto any form of ranked elitism; it doesn't accomplish much!
Another important thing to do is watch your LP gain and loss after matches. If your LP gain and loss are equal, or you're losing more LP that you're winning, stop playing ranked and play a few dozen games in normal. Your LP earning can tell you a lot about where you're going. Sometimes you're not going anywhere, so play normals and forget the stress of ranked games. Sometimes you're down on your luck and falling down the ladder, in which case you should definitely opt out for a while, grind normals for a while and come back later with a better chance at performing well. When you see your LP gain for winning is higher than it is for losing, that means grind, baby! The MMR system is giving you a chance to climb up the ladder, and with any sort of luck, you can take advantage of that lift and rise up the Elos.
Along this vein lies another important rule: Never play ranked tilted. Just like playing when you're at a disadvantage in LP gains and losses, playing when you're at a mental disadvantage can tax your performance, stopping a climb that you were making or losing traction and sliding down the hill. Be extra careful to make sure you don't play with any unnecessary mental disadvantages. This includes taking a break after a losing streak and muting toxic players on the spot rather than letting them chip away at your psyche. Both of these things are inevitable, but you don't have to let them affect your ranked performance! If you need to untilt, do something silly in the practice tool, play against bots, or find something outside of League to relax you. I wouldn't trust playing normals, ARAM, or RGMs to untilt myself personally, but if it works for you, go ahead. :)
If you play both normals and ranked, I would highly recommend playing a ranked game right after you just dominated in a normal one. The subtle boost in confidence for crushing it in one game can carry over into your next one, the same way negativity can be passed on and cause tilt. Unless you have something else to do, put that boost to good use and try a ranked game! This obviously doesn't guarantee a solid turnout, but attitude does matter, and destroying your opposition is a silent but powerful boon for your ranked career. (Part of the reason I have yet to be ranked is because I will never play a ranked game unless I get an S rank in normals, and with 4 wins out of 6 games, it's not looking bad! XD)
Finally, and perhaps most importantly, gather five lit candles and place them on a circle in a pentagram, placing six 6-sided die in position about the star: a face up one, two, three, four, and five around the circle, with a face up six in the center. Turn off the lights, provide an offering of some kind (a lucky trinket for example) and commence communication with the demons of RNG. You can rise Elo through your own improvement and following this thread, but the RNG demons remain as gatekeepers of the dreaded Promo Series, ready to strike Elo hell randomly upon those who line up to promote. You need to be in their good graces if you wish to succeed, so take this and any other measures necessary to appease them and spare their wrath for some other random ranked player. It couldn't hurt to try, right?
With that, I leave you with my best advice for how to better your ranked career with absolutely no gameplay-relevant skills involved. Good luck, and happy grinding!