To save payload, plan on moving almost everything you normally carry in your truck in your trailer or remove it completely. I'm getting Nazi on ours. I'm removing floor mats and glove box contents, moving tools and even the jack to the trailer. The kids can have a drink inside; If they want more, we can pull over and go back to the cooler.
The trick is to remember to move that stuff back when you need to separate the trailer and vehicle for some reason, like going to the grocery store.
Even better if you have sufficient payload capacity to begin with; That's one reason many full-timers upgrade to an F350 dually.