Seven pages of responses and I still don't see my "hacks" so here goes.
First off, I'm not as privileged as most of the other posters so my hacks don't have anything to do with J class seats or pods ... maybe some day.
1. If you are anything like me, I like sitting in an aisle seat, especially for places I have seen a million times from the air. So in the aisle seat, most people don't know that the armrest can go up. Just reach to where the armrest is connected to the seat and search for a locking lever. Push it and move the armrest up. Instant space to easily get in and out of your seat, especially for bathroom breaks and deplaning.
2. For situations where you are flying in a 2x3x2 or 3x3 configuration and you are two people, book a row with 3 seats and take the window and aisle or aisle and aisle (depending on the configuration). This will highly increase your chances that nobody books the middle seat and you have the whole row to enjoy between yourself and your partner.
3. Chat up the FAs if you are going to a city you haven't been before. Guaranteed they have some great places to check out that you hadn't though of.
4. When the drink cart comes around (remember, I fly economy), I always get a can of soda and a can of cranberry and a glass of ice. I then mix my own cran and soda and stay hydrated during the flight and with tip 1 from above, going to the washroom isn't a big deal.
Hope these help some of you.