Cross your fingers and hope the people around you like kids
There's always that "oh no!" moment, but then I had to fly with a small child so I've been on the other side. If you've got a small baby who wants to cry then there's very little you can do about it, so I feel sorry for the parents when it happens. My son was a perfect angel on his first long-haul flight at six months. It was a Virgin flight, and an hour or so before landing, the purser offered to hold him while we sorted ourselves out. She eventually returned him as the seat belt sign came on, he'd had a tour of the whole 747, it seems.
Of course, on the way home when we wanted to sleep on the overnight flight, he most definitely did not and it was a lot harder.
I was sat next to a mother and son last time into SFO, they weren't regular fliers so I was pointing out things through the window to them. The good one is to note the position of the wings on the ground and then where they are once in the air - the difference between the wings hanging from the fuselage and vice versa. We were on the left, so as we approached the Bay Area I told them what to look for out of the window (I've always wondered whether the local tourist board had influence over the flight path) as the aircraft banked left and the Golden Gate Bridge and Alcatraz were visible, and described the flight down the peninsular and the turn back up to the airport. I warned them about being almost in the water but didn't mention the Asiana incident until the wheels were on the ground. On my first flight into SFO I had an exit row seat and the flight attendant facing me gave me pretty much the same guided tour, so it was nice to be able to pass it on.