Here's some things that helped me finally climb to silver
-Practice a few new champions over and over in normal games to expand your champion pool, learn strong/meta champs
-Ban the champions that are really op right now, like Vi, Khazix, leblanc
-Ward a lot, watch the minimap, keep track of where the enemy jg is, use pings, follow your laner, look for opportunities to roam(push your lane first)
-Focus on last hitting, don't play aggressively in lane unless you have a clear advantage, don't push without warding, attack the enemy when their abilities are on cooldown (ex. lux just used her q on minions)
- record your games and watch them to see where you made mistakes
-if you are jg dragon control is important, so is ganking bot lane for first tower
-if you have a lead tell your team to group and push objectives, end games quickly dont throw