We study combined leptoquark (LQ) single and pair production at LHC at the level of detector simulation. A set of kinematical cuts to maximize significance for combined signal events has been worked out. It was shown that combination of signatures from LQ single and pair production not only significantly increases the LHC reach, but also allows us to give the correct signal interpretation. In particular, it was found that the LHC has potential to discover LQ with a mass up to 1.2 TeV and 1.5 TeV for the case of scalar and vector LQ, respectively, and LQ single production contributes about 30-50% to the total signal rate for LQ−l−q coupling, taken equal to the electromagnetic coupling. This work is based on an implementation of the most general form of scalar and vector LQ interactions with quarks and gluons into CalcHEP/CompHEP packages. This implementation, which authors made publicly available, was one the most important aspects of the study.