Most of my wargames are played on a 4ft x 3ft (120cm x 90cm) table on Kallistra hexagon tile terrain. I play in 6mm, 1/300, 1/285 scale.
Although Kallistra make roads and rivers to place on top of the standard tiles the roads are too wide for my scale and the rivers too regular.
I make my roads and streams about 2cm wide – which fits my standard troop base size – and rivers are 5cm wide, or almost the full hexagon edge.
I buy my hexagon tiles ready flocked with grass/earth colours. To make a stream or road I take a hexagon tile and mark the entry and exit points at the centre of the hex-sides. Next I take a paste brush about 2cm wide and liberally paint the route of the road or stream with water.
While it is wet I scrape the flocking to the edges of the road or stream route with a sharp knife. This has the effect of creating low banks on both sides. When dry I paint roads with a “pebble” tester pot from Homebase (a UK DIY store) . This shade was decided on after viewing European roads from above on commercial air flights. While still wet I sprinkle with fine builder’s sand and spray with matt varnish.
For streams I use a mix of blue, grey and brown tester pots and follow up with several coats of PVA glue to give a shiny surface.
To make marsh I use an unflocked tile. I still have a few from the days before I bought ready-flocked. I paint them as for the streams and then add flock and short lengths of cut sisal string or old paintbrush heads to represent reeds.