I think I've found a bit of a groove.  I'm pretty good with playing 3-4 games a night, and I've also found a good set of race matchups - I'm doing well in silver at ZvT and ZvZ.  I'm also getting better at creep spread and larvae injections!  Since I'm progressing bit by bit I can also see myself in a lot of the players I play, with them failing in their builds, getting timing wrong, or just plain guessing wrong, all as I did just a few days ago (and as recent as today!).

First game was a ZvZ.  Remembering an earlier game from this afternoon where I got roach all-in'd with some inept defenses, I decided to try that one again.  I started out hard on one base, as I was going to all game, and quickly teched up to liar.  From the replay I see that my opponent did a more traditional build style, and I quickly see where I could have been better - in a sec, though.  I got a spire as soon as I hit liar, and ran into a huge vespene wall.  I didn't have enough gas to get any sort of mutalisk force out, and I kind of knew I was bummed from there.  My opponent had expanded a few times and also placed some static defenses, which my mutas were too few to deal with.  Since my opponent had a massive income and larva edge on me, he went into roach/hydra and rolled me.  I had some static defenses that held for a short time, but I wasn't going to beat that force with a half dozen mutalisks.  GG to him, bad timing for me.
If I had scouted better, I would have seen that he was very undefended in the early game at both of his bases.  If I went for a good spawn of lings - a dozen's larvae worth or so - I would have been able to do a good amount of economic damage and maybe set myself up better.  As always, scouting!

Next game was a ZvT.  Immediately I knew I was going to go for ling/baneling, but I decided at the start to go for an expo after a pool.  I figured the terran would get his expo and hunker down a little bit, and I turned out to be right (I figure that's going to be the terran meta at silver level).  I got my second expo in place and mining and was able to summon a very good force of lings and banelings.  My opponent countered this with a few banshees but the banshee is not a very good counter for the ling.  Lings are too cheap and fast.  The banshees had trouble with some static defenses I had wisely set up (finally I learn!) so that bought me time to build up a nice chunk of ling/baneling and push at his expo.  It was lightly defended and I rolled in, killed all the scv's, and pushed into his main and took some more miners.  After that, he had 2 scv's, from the replay.  I knew I had a large edge there, so I transitioned into some tier 1.5-2 units - roach/hydra.  He couldn't get a big enough force out in time to deal with this and my army rolled.  GG from him, though I noticed later that he had a hidden expansion with a few miners.  I would have discovered that quickly, though.

Last game I played today was another ZvZ.  Lesson learned!  As soon as I saw the zerg race symbol, I know I was going for a one base roach all-in.  Wasn't falling for that again - and I caught myself from three games ago out.  I went for a fast roach warren and got 5 roaches out quickly.  I made a small push and noticed that he had did as I did earlier in the afternoon - fast liar into muta.  He had a few mutas out, but not enough to deal with the roaches I was pumping out - his drones tried to run away to the expo, but I also had some roaches there too.  GG from him.

Lessons learned: racial matchups are starting to form into place for me, though I haven't played a protoss today.  I still am unsure what I should be 'going for' there - fast roaches into hydra/roach?  That sounds like the best course of action, but I haven't had a chance to test that yet.  Also on the plus side is my larvae injections - they're really starting to pick up in consistency from horrible to just okay.  I think I'm going to ride these matchups into gold - I am 3rd in silver in my 'division' so hopefully gold is soon!