Besides gaming hobby stores you can get lots of great terrain modelling supplies from railway hobby shops. In fact they have been building terrain tables and dioramas for decades before wargaming became popular and the railway hobbyists and terrain companies have developed the best products and techniques available today. You can learn a lot from the websites like Noch and Woodland Scenics.
For trees I recommend to buy professional trees made by the company Noch or any other model railway model supplier. Go for 10cm high trees. they look the so realistic it really makes the table look great. They can also be mixed with cheaper ones, to create larger woodland areas. Simplest way to use them is glue a few to a base, then cover the base with some kind of flock.
Another option is to put individually trees on bases and put these bases inside a larger forst base. Then you can individually remove trees to get to the miniatures when necessary, but for a skirmish game like Godslayer, that’s rarely necessary.
Hills can be bought from several wargaming terrain companies like Zitterdes (who have a nice range of items).
In terms of buildings there are various options with different proce tags and quality.
For a simple easy solution to get a few scenery items on the table, Petco have some interesting Roman and Greek fish-tank ruins, so do some other aquarium companies. Such items are generally cheap simple bits that can get you started (and set the theme for Godslayer far better than medieval buildings).
There two I found particularly good quality:
And they also have some interesting ruins that looks south-east Asian in style. They could also represent one of the many dead cultures of Calydorn.
Pet shops also often have cool rock features for aquariums, which could be nice on a Troglotytes or Banebrood board. like this:
so with a few Aquarium pieces, a couple of hills and a few patches of woodland, you have enough to make a decent looking table with great options for playing.
All you need them is a board to play on. A great simple and cheap options is to buy a roll of static grass and glue it to polystyrene or polyfoam boards. Ideally they would be 24 X 48 inches, and then you just need a 2 of them for a standard table. You can even make a few different ones. The benefit of these is that they are easy to store and cheap and easy to make. The drawback is that they are flat and not detailed.
For a professional board you can use the same basic principle. Polystyrene or polyfoam as the base but now we build the bills into the board by layering and sculpting the foam. PVA wood glue is fine for sticking layers together. Then on top of these we put a thin layer of plaster, followed by a coat of green paint. Next you can cover the surface a section at a time with PVA glue and cover it with static grass. Get a puffer bottle form you railway store if you can because this make the grass stick up much better. Using multiple colors and lengths of static grass give more realism – darker in uphill areas, lighter in lowland areas. In the lowest areas use the longest grass.
Model Railway companies also offer tons of awesome bushes, reeds and even flowers. Layer these things one top of each other creating a patchwork of grass and bushes with different colors and heights, then garnish with some flowers.
Okay well that covers a temperate zone. For deserts, snow-scenes and water features there are plenty of tutorials online. Again the railway companies often have the best products for making snow, rivers and other water features.
If you want to buy some great looking Terrain pieces for Mortans, Halodynes and Wyldfolk, I would look at Grandmanner
Their buildings are listed as 28mm, but most doorways are 30-40mm high, so look really the right scale for Godslayer minis.
also has a large range of buildings. A lot of these are pretty much true 25mm scale, so a Little small for Godslayer minis in many cases (if you care abouit really accurate scale). If you are not that fussy about true accuracy then Monolith has a wide range. You could also add a layer of bricks under the building to artificially elevate it.
I have items from both companies, and GrandManner is a little more expensive but their products are stronger and larger in my experience.
You can of course build your own. Of course for this you need knowhow and practice, but its great to give it a try, then watch some tutorials, then tray again, and again. You will find your skill very quickly goes from zero to highly skilled!
Using polyfoam (Styrodor), polystyrene, artist foam-board and balsa wood you can build some great items. If you cover these with a thin layer of plaster they take on a realistic appearance. This takes time and practice but it offers also total control over whatever you want to make. There are some great tutorials on Youtube by Terranscapes
. This guy builds terrain professionally for money and he has developed some really great techniques as well as having found excellent materials and tools for terrain building.
Another possibility is to build terrain using bricks cast from plaster. Leading this market is Hirst Arts
They have a Roman set, which combined with the basic set and the tower set, offers a lot of possibilities for building Roman style structures. With Hirst arts, you buy the molds and then get yourself a bag of plaster of Paris and cast the individual bricks in the mold. They take about 20 minutes to set, then I finish them in the oven for 30 minutes at 80 degrees.
Combining Hirst Arts bricks with Folyfoam and foam board is another possibility.
At the moment I am building some terrain boards and planning on making tutorial videos of what I am doing. Right now I am still doing experimentation, preparation and time-consuming basic work, but in a couple of weeks I will start the first tutorial and I will be sure to post a link in the forum.