A famous poker quote: "There are 3 ways to play pocket jacks. They are all wrong"
But seriously, play them like you would play 9's or 10's. Limping is a strategy used to control pot size or trap loose aggressive players. Raising is used to isolate or to get marginal
hands like K 9 or Q 8 to fold. Some people either are too afraid or too aggressive with JJ. As with any hand you play, always have a plan as to what you will do, especially post-flop. I also know that you have to be prepared to fold JJ if you are aggressive and get played back. You have to know what ranges your opponents are willing to play, so you have a chance to leverage JJ if you do hit big. Folding at the right time is a big part of profitable play, but so is picking off the obvious
bluff. For example, let's say the flop comes 5 6 Q. If you know your opponent will play A 6, he probably stays in the hand. So it comes 2 2 on the river and turn, you may be able to get some value from him.