As fulltimers, we've been working on this issue for 3 years and feel we have a pretty good handle on the situation. We carry only what we need.
Look for dual purpose items. Try not to have more than one...
Avoid glass or china, they WILL get broken eventually.
Get silicone baking pans.
Save space by only having the number of items you actually need. ie: we only have 2 glasses or 2 cups for each type.....except wine glasses!
Living in an RV is a trade-off between having what you need, and fumbling over what you have and don't need, so choose wisely and be flexible!