Pulsing simply means instead of holding the fire button down for a couple of seconds at a time during priming, instead you ‘pulse’ the fire button – press it quickly for about one second.
If you’re using a unit with an adjustable wattage (e.g. the Titan 80W, which begins at 10W), pulse it a few times on one wattage before increasing the wattage by 1W and pulsing again for a few times. Usually, once the wattage hits about 8-10W, you can start firing the fire button for longer periods, e.g. 2-3 seconds at a time.
TIP: Monitor how you’re going with breaking in the coil by smelling the tank with each wattage you increase. If it continues to smell pleasant, the coil is being broken in well. If it smells burnt, you may have burnt the coil and you will have to use a new coil and prime it again slower.