Precision Moves

Twice this week I have had experiences where a position that was optically strong for me required surprising precision in order to make progress. The first time, I found the right move and emerged victorious. The second time... ahem.
Here, with the white pieces, I felt that my queenside majority should provide a stable advantage. My two bishops were also pretty nice. My opponent had just played ...a6, which I felt was unnecessary and weakening, but it took some thought before I considered the move: 1.Qb3! I suppose that a move like this really should jump out as obvious, but it seems so counterintuitive to block your own majority. Now it's hard to come up with a good reply for black. For example, 1...Rd7 2.Bb6 Qc8 3.Bd4 Qc7 4.Bxf6 Bxf6 5.Rxd7 Qxd7 6.Rd1, and b7 is falling. My opponent played:
1...Rxd1
2.Rxd1 Rc8? The best move is kind of hard to spot here. 2...Re8 3.Bb6 Qb8 would have put up the best fight, but white is still crawling over the queenside. 2...Rb8 runs into 3.Bb6 Qf4 4.c5 e6 5.Ba7 +-
3.Qxb7 and I was comfortably better and went on to win.

In this position, I had what appeared to be a very impressive attack. I had just won the e7 pawn, and I got... well, careless. I played:
1.Bxe5? Rd8
19.Bxg7? Nxg7 And only now did I realize that a consolidating move like Qc2 would run into a rook skewer on e8. I ended up sheding the pawn back to survive, and the game quickly petered out into a draw.

Instead, I had to play 1.fxe5, preserving the bishop to maintain my surprising pressure on the dark squares. From here, the lines are fascinating. For example, 1...Rc7 2.b4 Qa4 3.Nd5 Rc8 4.Qd1 and black is completely busted, 1...Rb7 2.Bc5!, 1...Rd8 2.Nd5 Qa3 3.cxb5 with the threat of Bc5! Obviously the trouble with these lines is that the key idea is different in each variation depending on how black replies, and I was just being... lazy.