Looking at your games -
Your rune pages are quesitonable -- You have T2 runes for a lot of pages, and you have a lot of hybrid tank/damage pages, but nothing tank specfic, espc. when you seem to play a lot of Rammus top. I'm also going to disagree with the scaling armor/mr runes you run. Games are typically over well before level 18, it's better to have the early game pressure imo.
Masteries -- Again, a lot of minor preferences, but - Runic Armor > Veterans scars / Insight > Perseverance / Tough Skin > Explorer / Feast or Exposed Weakness > Double edged sword. Those are pretty general preferences, but something to look at.
Aside from that, it's the basics. Work on KDA/CS'ing/Participation. Anything beyond that is hard to say, without playing with, or against you myself.