  We suggest several techniques to improve the toric codes and the finite-rate
generalized toric codes (quantum hypergraph-product codes) recently introduced
by Tillich and Z\'emor. For the usual toric codes, we introduce the rotated
lattices specified by two integer-valued periodicity vectors. These codes
include the checkerboard codes, and the family of minimal single-qubit-encoding
toric codes with block length $n=t^2+(t+1)^2$ and distance $d=2t+1$,
$t=1,2,...$. We also suggest several related algebraic constructions which
nearly quadruple the rate of the existing hypergraph-product codes.
