Another way to do it would be to use World space mapping, which uses the same coordinates regardless of object orientation or poly density. This may not be feasible for your objects or textures, but it's nice with procedural textures and such. One thing to also check is that the polygon seams between your terrain and the ground are as seamless as possible. A good way to do this is to filter the terrain altitudes so that the slope of the filter at zero is almost flat, then gradually ramps up. (a good example is the "young mountain" preset, but it doesn't have to be that extreme)