Dissipative Kerr solitons generated in high-Q optical microresonators provide unique opportunities for different up-to-date applications. Increasing the generation efficiency of such signals is a problem of paramount importance. We provided comprehensive analysis and found optimal conditions providing maximal pump-to-comb conversion efficiency (up to 100%) for the cases of a free-running and self-injection-locked pump lasers. The dependence of the optimal coupling rate on the pump power was revealed, in addition to the trade-off relations balancing the efficiency versus the number of comb line. The methods to increase the total comb power were also discussed.