How do you do microneedling?

The only instrument I am comfortable with is the Dr. Pen device. It oscillates rapidly and I advise people who use it to (1) get the one with the most needles – i.e. 36 needles, (2) go to a depth of no more than 1.25 mm, (2) hold it in each position for 10 seconds. The goal is to produce a wound that goes below the epidermis to the top of the hair follicles, where there are stem cells that this process can stimulate. Once a week is adequate. I would expect bleeding when held for 10 seconds.