D&D post-mortem

Yesterday I ran a D&D game. It went surprisingly well.
I had planned to start this adventure two weeks ago, but other things (house-sized mimics) kept the players from reaching this point in time. But I still didn’t feel prepared enough. And, due to holidays, the game was moved up a day. So I really didn’t feel prepared. I was scrambling the night before to plot things out.
And yet, it went great. I think it has been the best one I’ve run this campaign. (Although my players may disagree.) In fact, we played longer than planned just so we could hit the climactic scene. But the real treat was that we found out a lot about a player’s character’s history. Enough that that character is probably going to be retired to spend time with the family he didn’t know he had. (Not a problem for the player since he was running two characters.)
There are some things I think I could have done better. I could have plotted out the combat strategy of the big bad better. At the very least, I should take a close look at the abilities and have an idea as to the average damage and effects.
Hopefully, by writing them down here, I will remember these pointers in the future.