Suppose I tile $\mathbb{R}^3$ in a ($\mathbb{Z}^3$-)translation-invariant manner. If we insist on the tiling being regular, then we are left with only the cubic tiling. However, suppose that we allow for any finite number of symmetry-inequivalent flags. Then, I'm curious what tools there are to determine relations between the four quantities: 1) Average vertex degree 2) Average number of edges in a face 3) Average number of faces incident to an edge 4) Average number of faces in a volume.