By considering selected examples of new structure types, guidelines are set forth for the synthesis of new solid-state inorganic borates that are likely to have desirable properties for nonlinear optical applications. The structures of two new, noncentrosymmetric orthoborate fluorides BaCaBO3F and Ba7(BO3)3F5 demonstrate a feasibility for controlling linear optical properties and for producing noncentrosymmetric borates that melt congruently. The structure of SrLi(B3O5)3 represents an additional example of a noncentrosymmetric borate resulting from chirality of the B3O7 ring. In addition to potential practical value, crystals of the type AMOB2O5 (A = K, Rb, and Cs; M = Nb and Ta) provide a unique means for examining the structural dependent interrelationships of linear and nonlinear optical properties.