USB Booting Rasperry Pi

Hey Rob,
Sorry for the unrelated post, but how did you set up the Pi4? Any guide you can share?
I’m torn between installing this on a DSM or installing on a Pi4 SSD without waiting for an official version. An official way should come soon for PI4 as a beta firmware from 15/5 allows bootinbg from USB ( Running on a PI relying on an SD card is not an option…