We also have all Corell dishwear and plastic cups. My wife insists on having a couple real ceramic coffee cups, and I think that is the only item we have that's breakable.
We store our food items in tuppeware type containers, low sides, with no lids, and put as many as a shelf will hold. Then like items get put in each one. This keeps things from falling out when the door is opened, and keeps everything from sliding around.
Usually on the return trip home, our supplies are low. Those items are then put in one container and fit tightly as possible.
Things in the pantry (dog food, cat food, towels, hand towels,) stuff like that, just stay put. They don't move. Things in the refrigerator stay put. They don't move. Eggs stay in their carton, top narrow shelf next to the cooling fins, fits perfect, and never had a broken egg. Milk has it's little holder (gallon jugs), and all drinks go in the refrigerator door and in the crisper drawers. Nothing slides around on the wire shelves.
Our toiletries all all in a drawer, so if they move around, it doesn't matter. And the cabinet above the sink is usually empty, as we put our medicines and perscriptions there and then pack everything back in a small bag to bring back in the house. (we have so many perscriptions now, we feel like a traveling pharmacy!) If we travel from campsite to campsite (longer trips we just leave them on the shelves, but always open the door with caution! And ALWAYS make sure the toilet seat lid is DOWN.) Last camper, I had a perscription bottle fall in the toilet and down it went! That was a fun experience and something for another thread. Yes, I did get the bottle out of the black tank eventually. Our current camper, the toilet is on the opposite wall of the cabinet, but we still keep the toilet lid down.
Occasionally clothes will pop off the clothes bar in the closet, and sometimes they will actually come off the hanger. That's not so bad, but it does happen. We've had more problems with clothes coming off the hangers than anything moving around in the kitchen or living room cabinets.
Living room cabinets, and we have a lot of them! We use small plastic baskets there too. And some cabinets (oh you're going to love this ... are actually still EMPTY!) We use them to stuff our small fans or laptop computers, or DVD's in so they are tucked away when on the road. But mostly, those cabinets are empty.
Here's a couple very simple rules to follow with your new camper. I picked this up from a full timing web site and also from a couple of those billion dollar RV shows....
1. Pack tight. Fill up the space.
2. When you are done with something, put it back up immediately. Don't let it set around. If you do, you'll have constant clutter and it will drive you nuts. We practice this and it works. As soon as your done with something, put it up immediately. Dishes, pots, pans, games, DVDs, maps, clothes, pillows, food, everything! It only take a couple items out of place to make the small confines of an RV to feel claustrophobic and uninviting and frustrating!
Good luck and enjoy your new purchase!