Jumpstream: Focus on building stamina and playing slightly out of your comfort zone. For maps find something on a rate where you can get a 98-99% score on and then try getting a 95-96% score on .05X rate higher. For reading and pattern understanding there isn't really too much for jumpstream other than play more and don't manip patterns.
Jacks: Play denser stamina jacks to build stamina as it's a key component of general vsrg gameplay. You can also playing faster lighter jacks if you want develop a bursty less stamina focused playstyle. For dense jacks you can try to focus on the spaces where there aren't notes to figure out how to play the pattern. If you Have a difficult time trying to focus on missing note there may be a chance that the map that you are playing is a bit too hard for your skill level (although this may be because of not being used to the technique). Lastly Don't vibro jacks. It's much better to train jacks without vibro.
LN: Idk I don't play lns.
Streams: The 98-99 into 95-96 rate thing still applies but it also add a reading aspect that might be a bit challenging to get right. If you have problems trying to read a stream chart it's okay to lower the speed by .05x or more to get more acustomed to it. For technique I don't have much but there are definitely technique videos that you can find.
Useful stuff: rate changer
community/forums/topics/640981?n=1If you got any questions feel free to ask.