JJ is definitely a good hand, but can be also a tricky hand to play.
It is always depending on the situation. When you are preflop and there
was no action before you so far, there should be definitely a proper raise preflop. I mean no min bet or too low bet.
Then it depends how many callers you have.
Is there only one or two callers and maybe only one higher card on flop, then I would do a continuation bet. Not too small, not too big, so you can estimate, if someone hit something. But this is of course also depending on your oponents and your read on them. If you have a call station or not. So you need to adjust your game on them. Also need to see their reactions, when you get a reraise or so. Also you need to see how the board develops afterwards.
If you have 2 overcards on board, I would consider to fold.
If there was preflop a lot of limpers and you are late in position, I also would consider to limp in in some situations. Because then your hand may be already not good anymore preflop, because too many with A,K and Q at their
hands.
If there was preflop a raise and a reraise, I would consider to throw them away.
But everything is of course depending on the reads to your oponents.
What is also important is the size of your stack and the stage of a tourney.
If you have only 10 BB left and there was not much action before, they are
absolutely worth a push.
There are several things, that you need to take into account when playing JJ.