Random Thought #1: Thinking back on my last 4 or so years of gaming, I see significant shift of focus. I used to spend a lot of time on world building. This goes back to my childhood. Going back to my elementary school days, I made up cities, worlds, histories and even a galactic empire. This has carried over to gaming. I was very much a top down sort of GM. I am now the opposite...bottom up. I create just enough to get a campaign started and then make it up as I go.
Random Thought #2: Another shift in focus is moving away from spending time on house rules, class creation, etc. My focus now is more on the encounter. This is where the action is for me.
Random Thought #3: Gaming intent is important for group play. This is something I learned from decades in management and leadership and, more importantly, by playing music in a number of bands. Things go better when there is a common understanding of purpose and intention. Not that you need to bring in consultants and have facilitated touchy-feely pre-campaign sessions. I just think things go better when everyone at the table agrees with the premise and intent of the campaign, including style of play, etc. I have found this to be very true when playing music. If you want to make a group suffer for "your art," go play in an S&M dungeon with a group of masochists.