Reading is one of the most important parts.
But muscle memory can make you unable to reach higher BPM than the one you're building.
But at same time, play maps what you can't read, fuck up your reading.
So you have to mix.
Play really simple stuff but with high bpm. Always do only 1 play on each map each day. Play tons of different maps.
You also need finger control and stamina. Rhythm sense...
You can do all at once if you play mostly old maps. Add some long stream compilation. More old maps. Play a couple really high bpm maps (for you) almost at the end of the session, and finish your play session playing a couple easy 4.00* maps to slowly get your hands cold.
Never play high bpm and just quit the game after. Because you can injure yourself. There shouldn't be any pain, or weird feelings at any moment.
If you feel them stop play streams, and next day try to find a better possition.
Circles tell you what to do. Music tell you when. Hitsounds help your muscle memory and to understand what are you doing, and if it's going well or don't.
Read each circle is important to aim difficult streams. Better is your reading, more consistence you have.
Hitsounds are really important to play high bpm.
Techniques with fingers, hans and wrist are important to change between bpms.
To play high BPM you have to practice with the point where the computer register the key, do the smallest movment you can control and just use less presion on the key.
To make you understand, an example on a keyboard where 40g the key down half way to the bottom. The computer register you pressed the key when you press the key using 50g. And if you do 80g the key go down all the way to the bottom.
Having the finger relaxed on top of the key 2g of presion you down the key to the bottom using 80g to play 120bpm.
Having the finger putting 2g of presion you use 100g to play 140bpm.
Having the finger putting 40g of presion, you use an extra 20g to play 300bpm. And to releasse the key, you don't back all the way to the top using 2g, you back to the initial 40g, to repeat that 20g tap. (You always use more than the needed to make sure your key triggers always, and never using to much before tap, to don't tap by accident.)
The trick is to build muscle memory on those 20g (0'2cm) movment, so you can do it really fast and well cordinated.
It's more about coordination and finger control than speed itself. You can also build speed itself, so you can do more energy, what equals on less control needed to play higher bpms, but also more stamina burn.
Well interesting, but how the fuck do i practice that? Download some long stream practice maps, find a 220bpm map, put halftime nofail, practice that really small finger movment until you can get good at it. Then turn off Halftime and muscle memory should make you able to stream it easily.
You can play all the bpms using the same presion, but your bpms range will be poor.
I like to make a difference on the tapping style at 4 points.
<140bpm tap normal.
140 to 170bpm tap using a lot of finger movment.
170 to 200bpm burt tap, using arm muscles.
200 to 240bpm a bit of arm, fingers doing a really small pressure.
Over 240bpm to 300bpm a lot of key pressure before tap + really small movments.
This is different on everyone.
Keyboards matter a lot on tapping style.
I hope this help you and i explain myself good enought so you can understand it well.
Would be easier if i could give you finger sensations xD
I'm not focused on streams anymore, i expended 80% of my playtime on them. It's really enjoyable the sensation to stream high bpm, but need to much practice time and you would not be able to play any other pattern aside from the streams on the maps you will find them.
Also the maps high bpm usually are AR10 to make them easier to read, so you will need to learn high AR too, or just play only freedom dive CF
As general advice, once you can play the streams you find on maps on your level 4* low 5*, stop focus mostly on streams, and play maps what have a bit of everything. Tech maps are great.
As last advice acc is the most important thing streaming, focus on that. But not on the%, check replays at 0'5 speed and listen carefully each music beat and how the hitsounds match with the music. Understand the rhythm, and go build muscle memory.