I've got a ritual when I go to the theaters these days. I go to the morning shows/generally-very-empty screenings, scope out a good aisle-area seat in the especially vacant part of the auditorium... and when the first trailer starts, I head outside. I chill in the hallway for about twenty minutes, usually playing on my phone, and head back in for the actual movie. I've been making a point not to watch trailers for years now (pretty much for all the reasons you talked about), and since most of the big chains time their trailer time exactly (example: AMC has 20 minutes of trailers, plus regular turn-off-your-phone bumpers), I always make it back right on schedule for the movie proper.