The Maurice rules, came with a set of cards for terrain. There are about 5 or 6 different ones, such has plains, steppe, forested, built up, and even tropical.
These show the types of terrain that can be placed, the maximum number of each type, and sometimes a core type, which I think was one that each player had to place at least one of. This gave a theme to the terrain, while still allowing a good amount of variety.
We have used a method similar to the Saga one, where each player chooses a number between 1 and 6, and the sum of the two numbers is the total amount of terrain placed, then the players choose their pieces of terrain, and then alternate placing a piece of terrain.