Atmega328p won't program on custom PCB

You have installed a bootloader onto your new clone of the Mini Pro and you want to then load a sketch via that bootloader ?

If so, installing the bootloader should have set the fuses correctly for 16Mhz with external crystal.

If you are loading a sketch to processor which has an installed bootloader, then normally you use a USBTTL adapter and the sketch is loaded via the serial port D0 and D1