My scouting's gotten significantly better (ie, I remember to do it) and that's helped quite a bit. Unfortunately, it still has a long way to go (I got hit by a three-medivac drop recently that I had no idea was coming because I never remember to suicide an overlord for tech vT). That's going to be my focus going forward - that and spreading creep, which I'm still awful at.
I lost something like three straight ZvZs the other day thanks to unscouted mass mutas, which was frustrating. I've read up a bit on the matchup and counters to mutas in it in response, and it looks like the answer is: scout constantly, get an extra queen or two and a spore in each mineral line if you see him going spire, and get either hydras or infestors up sooner rather than later. Seems easy enough. Two of the games were at least close - one ended up being an elimination race that I "won" with roaches/burrow, except for not noticing that he'd sneaked an extra base since I started focusing solely on micro - and that one I couldn't finish off, not without an economy. Oops. Scouting, scouting, scouting.
I had another elimination race ZvP a few minutes ago that ended in the most embarrassing way earlier. I nearly held (one stalker and one immortal survived) while completely destroying his base - but he'd sneaked a nexus, and not only did I not find it in time, I didn't send a single one of my 30+ roaches back to clean up the stalker and immortal that were slowly picking off my buildings. If I'd sent them back to defend, I would have won easily instead of losing by literally seconds. Made me laugh my ass off when I realized that just as the game ended.
I still have a long way to go, and the scouting thing is way more difficult for me than it should be, but I definitely feel like I'm making progress, particularly in terms of game sense and understanding. I'm also still having tons of fun, which is just as important. Does anyone have any suggestions for reminding myself to scout? Set a timer to go off every 30-60 seconds and say "what's your opponent doing"? Do something about scouting every time I inject? Get an overseer or speed ovies as soon as lair finishes every game and use that to scout? That last one sounds like a good idea regardless, actually.