Using Baltic Birch plywood instead of Particleboard..
I build stuff out of wood, and I've found that if you need cabinets, countertops, and any sturdy structures inside the RV, using Baltic Birch plywood is the way to go.
It's much lighter than particleboard (Also known as "Sawdust Board" some places), and Baltic Birch not only is much stronger, it will not "melt" like particleboard, and will also sand out to a fine finish.
It can be had in different thicknesses. 1/4" does the trick for many applications, 1/8" for fine cabinets, and 1"2 for more bombproof furniture.
I buy mine from a specialty store that caters to home woodworkers, and these stores are found in most any large city. Timber, and Woodworker's Source are two in the Phoenix area.
Boondock traveler, Frugal, but never "cheap".