You may need to perform a spindle warm up procedure before conducting any carves, especially if it's cold in the winter months in the northern hemisphere or summer months in the southern hemisphere. You can tailor it to your own situation and just as with the spindle break in procedure, here is the gcode in raw format.

M3; spindle rotate CW

S6000; speed 6k rpm

g4 p600000; pause 10 minutes (10x 60,000 milliseconds)

S12000

g4 p420000; pause 7 minutes

S18000

g4 p180000; pause 3 minutes

M5; spindle stop

We recommend if you own a water-cooled spindle motor.  Run this warm-up with the coolant pump turned off.  This will help heat up your motor faster.

Know that your spindle should be warm to the touch before ramping up to carving speeds.  If your shop gets cold or even below freezing, consider throwing a moving blanket or something similar over top your motor to keep it protected over night.  

The provided .gcode file and its raw text are provided as a guide.

Based on environmental conditions you may need to run it longer or shorter, and you may need to modify the values if the "G4 P" command if it is not recognized as milliseconds and is instead converted from milliseconds to whole seconds.