No one knows how to play Jacks not even Phil Ivey or maybe he does.
People play Jacks too aggressively or too passively getting the balance right is an art. Jacks is a hand to go all-in pre-flop with when you are less than 10BB and up to 15BB in tourneys, stacking off with more than 30BB is a mistake unless you have a good read!
I advise playing Jacks in early levels as a set mining hand as you will generally win a small pot or lose a big one, when the antes kick in start 3 betting them.
This video tells you all you need to know