By using a mixture of hand crafting and digitally designed items printed either via FDM or SLA printers you can make wonderful looking dioramas, or tabletop terrain.
Here, I have started a custom order for a Warhammer 40k fort built into a cliff side. The project uses a foam base and foam rocks with some 3D printed walls (PolyTerra Eco PLA) and a laser cut plywood roof. Plus a few little scatter items such as barrels, ammo crates and trolleys made from Anycubic plant based resins.
An easy way to weather your walls, without having to paint the weathering details over the top is to paint splotches of dark browns and oranges over your primed walls, then spray small areas with hairspray and coat with salt! Leave this to dry then spray paint your walls the designed colours, once dry use a stiff brush to scrap away the salt leaving areas of patchy rust behind.