Read on twitter:

"Somebody stole all my credit cards, but I am not going to report the theft to the police. The thief is spending less than my wife did."
Henny Youngman

1: It's all about the upstroke. Worst HJs pull down too hard, hurting the skin by the tip. Remember: Gentle on the way down, more forceful on the way up.

2: Foreskin (if present) is your friend, lots of nerves. Feels good when it rolls over the tip. See also rule 1.

3: Tip is super sensitive, don't touch directly with unlubricated hand. You can / should glide over the edge of the tip on the up stroke, so long as there's skin or lube in between.

Most of all have fun practicing :)