I would have to agree. While I haven't got started on my first layout yet, I have been on these forums picking up tips from those with the experience for when I can get started. One thing for sure, you want the blue or pink foam insulation board not only under your layout but for use for constructing tunnels/hills.
Before that you may want to look at your foundation of the layout, by the photos it looks like several boxes holding up one end as well a table on top of another box on the other end. May want to make a strong foundation before investing time and money into the layout's trackwork and scenery.