Here is a great video showing the process of flashing your ESC with BLHeli, and how to enable oneshot125 mode for your mini quadcopter to get the best performance.
This video makes use of AFRO ESC’s and the AFRO ESC usb linker, but if you are using different ESC’s such as the Emax BLheli ESC, check out our guide on how to flash your ESC with BLHeli.