How to improve laning phase?

Hey, so I'll be upfront. I main Irelia (or trying to) and as everyone knows her power spike comes from her triforce, so about 15-ish minutes in game. My problem is getting to that point, the laning phase. Every game I make some decisions and sometimes they come out as successful or a failure, when they're good I get a kill or assert lane dominance, and when they're bad the enemy asserts lane dominance or I straight out die; I become inconsistent (look at my match history, seriously). I know I must being do something wrong and I have a vague idea of what I should do, however I have no idea how to do what I need to do, more so I don't understand really why the decisions I make are bad...except for when I die in a stupid way.

So yea, any tips on improving my early game? Any specific guide I can read/watch? Things to write down?

Thanks