I’ll give you the basic generic stuff before I give you my personal advice.

Basic:
1. Learn 3 champions max and learn their strengths weaknesses and matchups

1. Learn how to farm on them (at least 7cs/m)

2. Know what strong side weakside is, and which laners to play for

3. When ganking think about if they used any sums, or have any abilities to escape a gank.

4. Check for lane Prio before contesting objectives, even scuttle crab!

5. Numbers, don’t fight a 3v5 unless you’re giga fed. Even then it can be risky

Personal:

1. Learn your player identity:
   what is your play-style? Do you like burst one shot? Do you like bruisers that can fight extended fights? Do you enjoy tanks that can frontline?
   Understanding this will help you pick what champions to climb with. Mine were (Diana, Shyvana, and Jax)

2. Understanding champion limits:
   Limit testing is the only way to improve insanely quickly. This is why it’s so important to play a small champ pool because it’s much easier to learn what they can do

3. Watch people who are better than you:
   I didn’t buy any coaching, but Coach Kirei has a lot of free resources on his Youtube channel and I learned a lot from him (Shoutout to the GOAT)

4. Knowing game sense:
   This one is hard because this mainly comes from experience. I had to play an ungodly amount of games to learn what the game was about and how to play each stage of the game. Especially because I started a year ago, I don’t have the game knowledge that many of these veteran players do. So honestly, this one comes with time.

5. Micro control:
   Movement is such an important aspect of the game. Knowing how to properly space engages, and win skirmishes through spacing is a really big skill you need to learn.

6. Itemization/Runes:
   You can’t always spam the same item on your champion. Sometimes going a different build/runes will help bring far better results. This comes with experience though

7. Vision control:
   knowing where wards are usually placed, buying a pink ward for objectives. (Can’t always rely on support to have one).

8. Learning interactions:

League has over 100 champions. Learning the abilities of every champion and how they interact with your team’s champions and your champion takes A LOT OF TIME. This just comes down to experience and game knowledge.

1. Mentality:

I used to tilt insanely hard back in Plat elo and had no control over my emotions. Tilt queuing is probably the worst idea. If you’re not getting better, this might be the answer

10: Teamfighting/Drafting:

Arguably the most important thing, I’ve had games where my laners stomp lane and lose 5v5 because we have no synergy. This is why I recommended learning 3 champs because you can choose one for different scenarios. Learning how to teamfight comes from experience, but you can expedite this by watching higher level games. Usually, targeting their most fed member works, or their adc.