I think up till move 34 my moves are pretty easy to see why. In fact all game was like that.
He made a mistake on his 21st move but he had his kingside all crammed up.
22. bxd1 in order to 23 Rxd1 and so weaken even more his king side pawns.
24 Nf4 was a mistake. I was up in material so had no problems in exchanging material. And with the follow up of this move i would take control of another file.
28 kb7 i was trying to make my king mobile and help the a and b pawns into promotion.
30. re1 trying to take away his rook or make him flee the scene. Probably a mistafe if he took my rook!
34 kc4. I think this was a good move as we was atacking the b4 square.
34 ka6 one of my favorite moves of the game. I was thinking about checking the king and drive him away from the b4 square.
35 b5+ plus was practically assured.
37 rc8+ and away goes the bishop securing my a-pawn promotion.
39 re1 trapping the king!
40 kb7. This was like a warning for him not to take my f-pawn unless he moved his king what would him lose a tempo.
42 rc7+ the natural move. He didn't pay attention to my warning!
From then on everything was prety much in its place.
Sorry for the poor analysis but i'm learning to this right now and i'm now starting to pay more attention to my moves and study my games. Even though I usually make some blitz type blunders.