Model Railway: Details

Baseboard

• Main horizontal sections.

Mainly cheap chipboard in small sections with softwood framework for rigidity for support at different levels.
• Gradients (slopes).

A word of warning to anyone thinking of building a sloping, curving section - it's not easy. If I had known just how difficult it would be, I think I would have had the gradient on a straight section of track and kept all curved sections horizontal. Having said that - I'm very pleased with the way it looks now.
I cut strips of thin (fairly flexible) chipboard into arcs to support the track on the gradients. These are roughly cut oversize to provide a surface either side of the track to attach the plaster landscaping. The short lengths are joined with small lengths of the same material so that you can twist and bend the surface. I extended the softwood frame to anchor this surface at key points. I just used offcuts of wood to pack it until it looked right - later when I laid the track and ran trains along it I found I had to adjust the height at various places.
• Supporting legs.

Vertical chipboard strips at the back flush against the wall (cheap and cheerful). Bolt-on metal legs at the front.

Track

• Hornby turnouts (points), and lengths of flexible track bought from a local shop.

I use tiny screws to hold it in place. Although they're more expensive, these are much better than the usual pins because you don't have to hammer anything - subjecting your layout to "richter 7 earthquakes".
• Rail joints at sections.

I leave a short length of track free (not screwed in place) and rely on the rail joiners (fishplates) to hold the track in place. You just slide the rail joiners all the way onto one rail to separate the sections.
• Electrical connections.

I solder directly to the (outside of) the rails to make a reliable connection.

Scenery

• Hills, slopes, roads.

The main bulk of the features is provided by screwed-up newspaper. I then cover this with strips of rag soaked in plaster (50/50 water/plaster). I have found this sticks very well to chipboard i.e. you don't need to make any special arrangements such as attaching chicken wire. Depending on thickness, temperature etc, this can take up to two days to dry.
The top (visible) layer is made by spreading plaster mixed with various substances to give it texture. Various grades of sand give good effects but if you want to try it be warned - it's very tough when dry so it's difficult to modify. Also remember that the sand will tend to sink so you have to keep stirring and, once you've applied the mixture,  "tease" the surface with a brush, fingers etc to break it up - you may have to do this a few times before the mixture has dried. Fine sand is good for short grass, soil and road surfaces. Coarser grades (even with very small stones) are good for crumbling edges of hillsides etc.
Synthetic "wool" - (bulky fibers) used for stuffing toys etc is good for "wild grass" effects. Tear into small pieces and pull on the edges to make them thin and flat . Dip into the plaster mixture, lay it on top and "rough it up a bit" with your fingers.
• Tunnels, bridges.

I first make something structurally sound with chipboard etc and then add a layer of "brick" or "stone" to the visible areas using "air drying clay" (such as Das).

Buildings

• Station building is a Wills kit, Hornby water tower and engine shed