Save yourself some time and skip drying the car after washing. Also while detail spray is fine for this step I usually use dawn dish washing soap mixed with water as a lubercant much more affordable, just a few drops in a spray bottle works fine.. Lastly while it depends on how much of the car is getting Clyde I usually cut those clay bars in half vs thirds.
While personal preference I never run a buffer over paint without laying it first. It's rare to find squeaky clean paint that requires buffing. I also still prefer using clay vs nano skin towels.