Hosting a legendary base 95 speed in the Nu tier, Jynx is one of the fastest pokemon in the game. She can run a plethora of sets and has that legendary speed tier to outpace most of the metagame. Speaking of sets, the two most common sets she can run are the scarfed and sub nasty plot. Coming from 115 base special attack, those psychic attacks and Ice beams will be doing a big chunk to things that are weak to them or even doing a little bit to types that resist it. Some of the moves Jynx gets are stuff like Trick Room or Calm mind, but Jynx does not have to sufficient defenses to keep something like that up. Plus, Jynx is a fast mon in the NU tier, so you really can't use it with TR.
Even though Jynx is a blessed mon, she also has her flaws. Base 50 defense is not too good to keep her alive on the physical side, so you have to predict around pokemon like Skuntank or Sawk and you also have to watch out for any super effective moves. While Ice/Psychic is an interesting typing, it does give her weaknesses to a lot of things in the tier,therefore requiring you to play around those. Any pokemon with sucker punch or Pursuit can take her down if they can take a hit from either Ice Beam or Psychic.
Aside from that, what sets have you guys been running ? How much effect have you used Jynx to ? What teammates go well with Jynx ?