One tip you would give me to climb ELO.

Don't forget to ward a lot http://www.monstropedia.org/images/thumb/2/2b/Kappa-1.jpg/180px-Kappa-1.jpg

Map awareness.

Check champion.gg and play what has the highest win rate.

Play games. The more you play, the better chance you have to improve.

If you're playing top lane: know when and where to engage, be wary of the jungler (don't ward in the river bush; ward tri-bush or scuttle), buy defensively is you are losing, buy offensively if you are winning, buy defensively if you are on par with your opponent, you do zero damage to the tower in the beginning, it's best to farm minions instead, know how to freeze lane, know how to push lane, push lane after the opponent recalled to deny farm/exp, know how to farm under turret

If you're jungling: watch this: https://www.youtube.com/watch?v=RQdZSs9_kV4 and use it to tell when to gank the lanes

If you're going mid: same as top lane, except ward one side of the river, and stay near that side

If you're going adc, positioning is extremely important, try to farm up as you usually scale off late game, don't poke unless you cannot kill any immediate minions, coordinate with your support, wait for your support to engage before you engage

If you're support, get warding trinket first, rush sightstone, sell warding trinket for upgraded oracle lens, try to upgrade your support item if possible, else build full ap/tank

Patience