Garbage: any hints or helpers or trash tips

We spend half our year in a 5th wheel and the other half in a sailboat. The sailboat is the larger challenge. When we are out in the San Juan islands, mostly those that are state parks, garbage is pack it in/pack it out. Also our refrigeration is more limited. So the garbage question starts with what goes on board in the first place. We buy meat in smaller quantities, but more often, so I get it from the butcher counter and have it wrapped. Or we'll buy small quantities of frozen fish that will be thawed the third or fourth day out. We also pressure can meat in the fifth wheel in the cold weather for consumption on the boat. The canning jars have their place on the boat whether they are full or empty. I try to buy stuff from the bulk food dept. so I can use containers that work with our storage areas. We use a couple of the smaller Brita filter pitchers for our water. We got the smaller ones because they fit in the door of the fridge in the fifth wheel, but they stay on the counter on the boat or in the sink when we're underway. That saves tremendously on space over using bottled water.
It's been a huge adjustment as I was one of those who loves a well stock larder when we lived in our house. Now when I shop I have to consider "Where am I going to put this?"