Good Info on packing your RV and Why
Sounds silly: Love your GVWR & MPG! Don't fill every nook! Making good choices about what to pack and more importantly what not to pack will help you have a safer trip and will put a few bucks back in your wallet with higher mpg.
You don't have to use every space!
For the travel kitchen: do not overpack food or cooking supplies. Take the time to create a meal plan and pack the food you will be using on the trip. Resist the urge to pack a few cans of this and a few packages of that as a backup. Those extra canned goods and packages just add weight. Having canned goods in reserve is OK at home but not on the road. Same for the supplies, only pack what you need to prepare your planned meals. Keep it simple and spend more time enjoying the destination and less time cooking and cleaning.
For the handyman: take a basic set of RV tools and yes bring the duct tape. But do not fill your RV up with tools for every possible situation. As RV travelers we all DIY, which saves money, but carrying tools around for every possible need is not the best use of space and weight.
Storage compartments: do not fill every square inch. Take what you will use and do need but avoid the natural tendency to fill all those storage cabinets. And a benefit of packing only what you will use is you do not have to unpack it when you get home!
About the tanks: If there is potable water at your destinations fill your fresh water tank about one quarter full and fill up at the destination. Going 1 hour up the road to a beach location? Probably don't need a full tank, so buy what you need and you'll increase your mpg from carrying less fuel on board. Better yet, buy what you need for one way and fill again with enough to get you home.
Lighter is better, so if you can pack a light weight version of something choose it.
Just a few common sense choices that will help you get better MPG, be sure you aren't over you GVWR, and hopefully make your trip more enjoyable!