Having finally stumbled on the layout I needed to build some scenery. I used a lot of builders spray foam to create mountains with tunnels, soon discarded. Gash wood from an old bookshelf was used to create levels and inclines but you need to make mistakes to hone your progress and I have made many. I tried to make houses out of balsa wood but it is difficult working to scale, a normal house to scale is no more than two inches tall. I have a huge pile of churches, castles, tower blocks, warehouses that are all too big. Eventually I bought some scale model kits from Metcalfe models, they have solid cardboard inners and the outside are predecorated thin card. They are fiddly but if you take your time they are ultimately very good.